This was CNBC's live blog tracking developments on the war in Ukraine. See here for the latest updates. 

Russia unleashed a wave of missile attacks across Ukraine overnight, with Kyiv and five other cities among the targets. The strikes damaged buildings, setting some ablaze, and killed and wounded civilians.

The barrage of missile attacks came as Ukrainian President Volodymyr Zelenskyy denounced Russia during several speeches at the U.N.'s summit in New York this week, warning of Russian "mass destruction" and calling on global leaders to unite with Ukraine against Moscow.

Zelenskyy left New York for Washington, where he is meeting with U.S. lawmakers, administration officials and President Joe Biden with the aim of securing more aid for Ukraine, particularly in the area of air defense.

In other news, Poland has dealt a serious blow to Kyiv after it said it will no longer supply its neighbor with weapons, as a rift over agricultural exports deepens.

Warsaw has been one of Kyiv's staunchest allies since mutual foe Russia invaded Ukraine in February 2022. Poland has donated weaponry, tanks, Soviet-era fighter jets and provided military training to Ukraine's armed forces. Ukraine, which has made repeated pleas for more weaponry from its allies, has not commented on the move.

President Joe Biden welcomes Ukrainian President Volodymyr Zelenskyy

President Joe Biden welcomed Ukrainian President Volodymyr Zelenskyy to the White House on Thursday as the embattled leader seeks to shore up additional support for his war-torn country.

Biden was seeking a "battlefield perspective" from Zelenskyy in their meeting, according to National Security Council spokesman John Kirby.

Speaking in the Oval Office before the meeting, Zelenskyy thanked the United States, saying the countries are "really truly allies." He said he intended to talk about weapons systems with Biden, "with a special emphasis on air defense."

"I am in Washington to strengthen Ukraine's position to defend our children, our families, our homes, freedom and democracy in the world," Zelenskyy said.

Biden called Ukraine a "partner" and said he was working with other G7 allies to formalize a commitment to the country's long-term security.

Biden announced a $325 million military aid package during the meeting with Zelenskyy, NBC News reported.

— Emma Kinery and Scott Mlyn

First grain ship sailing from Ukraine since Russia halted grain deal reaches Istanbul

A ship carrying grain from Ukraine — the first to set sail from the country since July, when Russia reimposed its blockade in the Black Sea — has reached Istanbul safely, according to marine traffic monitors.

The vessel, named Resilient Africa and carrying a Palau flag, left Ukraine's Chornomorsk port on Tuesday carrying 3,000 tons of wheat and bound for Israel, Ukrainian authorities said.

The journey represents the first successful Black Sea trip for a vessel coming from Ukraine since Russia pulled out of the UN-brokered Black Sea grain initiative in July, under which it had previously allowed ships transporting grain for export to leave Ukraine safely.

After withdrawing from the deal, citing displeasure with what it deemed to be unfairness toward Russian exporters, Moscow began bombing Ukraine's ports and grain storage facilities.

Ukraine is currently testing out a new alternative sea route in waters controlled by NATO members Romania and Bulgaria.

Ukraine is one of the world's largest producers of grain, most of which was exported internationally before Russia's full-scale invasion.

— Natasha Turak

Zelenskyy faces a tougher crown during Washington visit as some Republicans sour on Ukraine support

The White House is seeking $24 billion in additional aid to Ukraine, which it hoped would be passed alongside a continuing resolution to avoid a government shutdown as federal budget negotiations continue.

The measure has bipartisan support in the Senate. But it has been held up in the House of Representatives, where some members, like Rep. Marjorie Taylor Greene, R-Ga., have said they will not support any additional aid.

House Speaker Kevin McCarthy, R-Calif. is in a difficult position on the issue of Ukraine due to a slim GOP majority in the House, which gives individual Republican lawmakers leverage to pressure him to accede to their demands. Conservatives balked at McCarthy's proposal last week to pair Ukraine aid with additional border funding.

McCarthy agreed to meet with Ukrainian President Volodymyr Zelenskyy privately during the latter's visit to Washington on Thursday, but did not offer a forum for him to appeal to the full House of Representatives as Senate Majority Leader Chuck Schumer, D-N.Y. did in the upper chamber.

Read the full story here.

— Emma Kinery

Defense Secretary Lloyd Austin meets with Zelenskyy at the Pentagon

Ukraine's Volodymyr Zelenskyy met with U.S. Secretary of Defense Lloyd Austin at the Pentagon after meeting with members of Congress at the Capitol.

He then took part in a wreath-laying ceremony at the Pentagon's 9/11 memorial alongside his wife, Ukrainian First Lady Olena Zelenska, Defense Secretary Austin, and U.S. Chairman of the Joint Chiefs of Staff Gen. Mark Milley.

— Natasha Turak

Ukraine pushes for diplomatic solution with Poland, Slovakia on grain

Ukraine agreed to license its grain exports to Slovakia on Thursday and pushed for a deal with Poland to end restrictions by its neighbors on grain that it has been forced to send overland since Russia's invasion last year.

Slovakia, Poland and Hungary imposed national restrictions on Ukrainian grain imports last week after the European Union executive decided not to extend its ban on imports into those countries and fellow bloc members Bulgaria and Romania.

The countries have argued that cheap Ukrainian agricultural goods meant mainly to transit further west and to ports, get sold locally, harming their own farmers. The EU, which imposed its ban in May, let it expire on Friday after Ukraine vowed to tighten controls.

For much of the last year, some 60% of grain from Ukraine, one of the world's biggest exporters, has transited through the five eastern EU countries.

The row escalated as Ukraine, which turned to land routes to the west after a de facto Russian blockade of its Black Sea ports, filed a complaint with the World Trade Organization (WTO) over the bans and threatened retaliatory import restrictions.

Read the full story here.

— Reuters

Russia hits Ukrainian energy facilities in biggest attack in weeks

Russia pounded energy facilities across Ukraine on Thursday in its biggest missile attack for weeks, firing what Ukrainian officials saw as the first salvo in a new air campaign against the national power grid.

Power cuts were reported in five Ukrainian regions in the west, center and east, reviving memories of multiple air strikes on critical infrastructure last winter that caused sweeping outages for millions during the bitter cold.

Officials said at least 18 people were wounded in the air strikes, including a nine-year-old girl, and a regional governor said two people were killed in separate overnight Russian shelling.

"Winter is coming. Tonight (Russia) renews missile attacks on Ukrainian energy infrastructure," lawmaker Andrii Osadchuk wrote on platform X.

Russia's Defense Ministry said in a statement its attack hit military industry facilities, radio intelligence installations and centers for the training of sabotage groups. It said it struck all its targets.

Ukraine has been racing to repair infrastructure after the attacks last winter damaged nearly half its energy system and forced grid operators to impose regular rolling power cuts.

Read the full story here.

— Reuters

Ukrainian President Zelenskyy in Washington: Photos

— Getty Images

'If we don't get the aid, we will lose the war,' Schumer quotes Zelenskyy as saying

U.S. Senate majority leader Chuck Schumer spoke to reporters after meeting with Ukrainian President Volodymyr Zelenskyy in Washington, and cited the leader's stark description of his country's needs just over 18 months into Russia's invasion.

"There was a single sentence that summed it all up, and I'm quoting him verbatim, Mr. Zelenskyy said: 'If we don't get the aid we will lose the war'," Schumer said.

His comments came after Zelenskyy addressed the Senate behind closed doors in the Capitol building's historic Old Senate Chamber. Senator Chris Murphy posted descriptions of the meeting on social media platform X, saying that the Ukrainian leader received several standing ovations.

Zelenskyy told reporters after the meeting, "We had great dialogue." He is scheduled to meet with President Joe Biden later in the day.

— Natasha Turak 

UK authorizes charges against five people on suspicion of spying for Russia

The UK's Crown Prosecution Service (CPS) has delivered charges against five people it suspects of spying on behalf of Russia.

The individuals, three men and two women, are charged with "conspiring to collect information intended to be directly or indirectly useful to an enemy," prosecutors said. They are all Bulgarian but have been living in the UK and are between the ages of 29 and 45, the CPS said.

"The CPS has authorized a charge of conspiracy to conduct espionage against three men and two women suspected of spying for Russia," Nick Price, the head of Crown Prosecution Service's special crime and counter-terrorism division, said.

The accused individuals are scheduled to present themselves at the Westminster magistrates court on September 26.

— Natasha Turak

Russia temporarily restricts motor gas and diesel fuel exports

Russia announced a temporary halt on gasoline and diesel fuel exports to prevent domestic market shortages, as prices on the Russian market have soared.

"The government introduced a temporary restriction on exports of motor gasoline and diesel fuel to stabilize the domestic market. The decision was made to stabilize fuel prices on the domestic market," a government statement said, without giving details as to what specific measures would be implemented.

Prices of those commodities have spiked domestically amid a weakened ruble, higher oil prices globally and supply disruptions at Russian refineries undergoing repair works.

The news follows Moscow's decision one week prior, in coordination with OPEC partners, to extend a voluntary curb on crude exports through to the end of the year to buoy oil prices.

— Natasha Turak

Zelenskyy meets with U.S. lawmakers in Washington

Ukrainian President Volodymyr Zelenskyy met with U.S. lawmakers at the Capitol building during a visit to Washington, where he stressed his country's need for more military support, in particular air defense.

"Today there are important negotiations in Washington. Air defense for Ukraine is among the top issues," he wrote in a Telegram post, according to a Google translation. "More air defense, more support for Ukrainian soldiers on the front lines."

Zelenskyy met with leaders of the House of Representatives and House national security committees, and addressed the full U.S. Senate in a private session.

The Ukrainian leader is also set to visit the Pentagon, meet with President Joe Biden, and give an address at the National Archives museum.

— Natasha Turak

Russia says 'military industry facilities' hit in multiple Ukraine strikes

Russia's defense ministry said it targeted "military industry facilities" in its overnight attacks across Ukraine last night.

"The Armed Forces of the Russian Federation carried out a multiple strike with high-precision long-range air-launched weapons and attack unmanned aerial vehicles on military industry facilities, as well as radio intelligence and training centers of sabotage groups of the Armed Forces of Ukraine," the ministry said on Telegram. It did not provide evidence for its claims.

"The goals of the strike were achieved. All objects were hit," the ministry said.

Russia launched attacks on Kyiv and a number of Ukrainian cities on Wednesday night with President Volodymyr Zelenskyy saying "infrastructure" had been targeted. At least three people reportedly died in the attacks and others were injured, including children.

— Holly Ellyatt

Air defense for Ukraine top of my agenda, Zelenskyy says ahead of Biden meeting

Ukraine's President Volodymyr Zelenskyy said air defense for Ukraine is at the top of his agenda when he meets President Joe Biden in Washington Thursday.

"Today, we will have important negotiations in Washington. Air defense for Ukraine is among the top issues," he said on Telegram. Cities across Ukraine were the target of a massive missile attack on Wednesday night in which at least three people were killed and a number of civilians injured.

"Most of the missiles were shot down. But only the majority. Not all," Zelenskyy, who has been in New York this week attending the U.N.'s General Assembly, said.

"Thanks also to every country that has already provided Ukraine with anti-missile systems. We are working to completely rid Russia of its terrorist potential. We have to come to this result. More air defense. More sanctions. More support for Ukrainian soldiers on the front lines," he said, adding that "Russian terror must lose."

Russia denies that it targets civilian infrastructure despite numerous instances of civilian buildings being attacked during the war. Ukraine has accused Russia of numerous war crimes.

— Holly Ellyatt

Ukraine targeted Russian military airfield in Crimea

Ukraine's military confirmed that it targeted Russia's Saky military air base in occupied Crimea on Wednesday night.

The Strategic Communications Directorate of Ukraine's armed forces said on Telegram Thursday that "on the night of September 21, the defense forces of Ukraine struck the military airfield of the occupiers near the city of Saky in temporarily occupied Crimea."

Earlier Thursday, a source at Ukraine's security service gave NBC more detail about the attack, saying the Security Service of Ukraine and navy launched a strike at the Saky military airfield in Crimea, inflicting "serious damage."

The source, who asked for anonymity because they aren't authorized to speak publicly about operations, said there were 12 combat aircraft (Su-24 and Su-30 fighter aircraft) at the airfield, a Pantsir missile system and a UAV (unmanned aerial vehicles, or drones) operator training base.

"Strikes hit the targets and caused serious damage to the occupiers' equipment. Drones were used to defeat the enemy, which overloaded the Russian air defense system, and then they [Ukraine] launched Neptune missiles," the source said.

"The occupiers cannot feel safe on the occupied peninsula," the source said, implying more attacks would come in future.

Russia's Ministry of Defense said Thursday that Kyiv had attempted to attack "objects" on Russian territory with drones but said it had thwarted the attack. It did not mention the Saky (or Saki, as Russia spells it) airbase by name.

"On the night of September 20-21, an attempt by the Kiev regime to carry out a terrorist attack with aircraft-type unmanned aerial vehicles on objects on the territory of the Russian Federation was stopped. Air defense systems over the Black Sea and the territory of the Republic of Crimea destroyed 19 Ukrainian UAVs."

— Holly Ellyatt

Pressure mounts on conscripts a year since Putin's 'partial mobilization'

A year ago today, Russian President Vladimir Putin announced a "partial mobilization" of around 300,000 Russian reservists in Ukraine. The move sent shock waves through the country as Putin established Russian society on a firm war footing, and thousands of men tried to flee the country to escape the draft.

In the last week, the chair of the Russian State Duma Defence Committee reiterated that mobilized personnel were obliged to serve for the duration of what Russia still calls a "special military operation."

Britain's Defense Ministry noted Thursday that former general Andrei Kartapolov also made a made a new admission that shed light on "the stark situation at the front" when he said that it was not possible for personnel to be rotated out of the operational zone during their service.

"The absence of regular unit rotations out of combat duty is highly likely one of the most important factors contributing to low Russian morale, and the Russian Army's failure to conduct higher-level training since the invasion," the ministry said in an intelligence update on X, formerly known as Twitter.

"The lack of such training is highly likely contributing to Russia's difficulties in conducting successful complex offensive operations."

— Holly Ellyatt

Russia says it thwarted Ukrainian 'terrorist attack'

Russia's Ministry of Defense claimed Thursday that its forces repelled a drone attack by Ukraine against Russian-occupied Crimea, and several regions in Russia itself.

"On the night of September 20-21, an attempt by the Kiev regime to carry out a terrorist attack using aircraft-type unmanned aerial vehicles on targets on the territory of the Russian Federation was thwarted," the ministry said on Telegram in a post translated by NBC.

"Air defense systems destroyed 19 Ukrainian UAVs [unmanned aerial vehicles] over the Black Sea and the territory of the Republic of Crimea, one each over the territories of the Kursk, Belgorod and Oryol regions," No further details were provided and CNBC was unable to immediately verify the information.

Belgorod, Oryol and Kursk are among a number of northwestern, central and southwestern Russian regions that have been targeted increasingly in recent months.

Ukraine remains typically tight-lipped about attacks against Russian territory and NATO members have asked Ukraine not to use NATO-supplied weaponry against Russia itself, fearing this would be seen as a direct attack by NATO against Russia. It is therefore believed that Kyiv uses mainly Ukrainian-made drones in any attacks against Russia. It announced in summer it is ramping up the production of domestic-made UAVs.

Russia unleashed a wave of missile attacks across Ukraine overnight, with Kyiv and five other cities among the targets. The strikes damaged buildings and killed and wounded a number of civilians.

— Holly Ellyatt

Ukraine says it destroyed 36 cruise missiles following nighttime attack

Ukraine's Air Force said it destroyed 36 air-based cruise missiles after a large-scale Russian attack last night.

"Around 3:40 a.m., the Russian invaders attacked Ukraine with Kh-101/Kh-555/Kh-55 air-launched cruise missiles," the air force said on Telegram, noting that 43 cruise missiles were launched from 10 TU-95MS Russian strategic bomber aircraft.

"Missiles were launched in several waves. They entered the airspace of Ukraine from different directions, constantly changing their course along the route," the force said in comments translated by NBC.

The air force said it and Ukraine's defense forces destroyed 36 cruise missiles, adding that "anti-aircraft missile forces, fighter aircraft, the Air Force, units of mobile fire groups of the Defence Forces of Ukraine and other means were used to repel the strike."

It noted that Kharkiv was attacked with S-300 anti-aircraft guided missiles.

— Holly Ellyatt

Russia unleashes wave of attacks across Ukraine

Russia unleashed a wave of missile attacks across Ukraine overnight, with Kyiv and five other cities among the targets. The strikes set buildings ablaze and killed and wounded civilians.

Air alerts sounded across the country as Russia launched a barrage of missile attacks on the capital, where seven people including a nine year-old girl were injured, as well as Kherson, where three civilians were killed and others injured.

Kyiv Mayor Vitaly Klitschko posted on Telegram that "Kyiv survived another night attack by Russian barbarians," saying that buildings had been damaged and that there were power outages in some parts of the city.

Kharkiv, Lviv, Rivne and Cherkasy in central Ukraine were also among the cities targeted, regional Ukrainian officials reported on Telegram, posting images of emergency services trying to rescue people from the rubble of damaged or destroyed buildings in some cities.

The attack came hours after President Volodymyr Zelenskyy delivered a speech to the U.N.'s Security Council on Wednesday, calling for Russia to lose its veto power within the council. He also presented a Ukrainian peace plan at the summit. He's due to travel to Washington on Thursday to hold private meetings with President Joe Biden.

— Holly Ellyatt

Poland deals Ukraine a blow, saying it will no longer supply weapons

Poland said Wednesday that it will no longer supply its neighbor Ukraine with weapons, amid an ongoing and deepening rift over agricultural exports.

"We no longer transfer weapons to [Ukraine], because we are now arming Poland," Poland's Prime Minister Mateusz Morawiecki said Wednesday on the X social media platform, previously known as Twitter, according to a Google translation.

"Ukraine is defending itself against the brutal Russian attack and I understand this situation, but as I said, we will protect our country," he added.

Warsaw has been one of Kyiv's staunchest allies since mutual foe Russia invaded Ukraine in February 2022 but the latest comments followed a dramatic deterioration of relations between Kyiv and Warsaw this week.

A recent dispute over Ukraine's agricultural exports — which have had to be transferred via eastern European countries while Russia has effectively blockaded grain ships leaving the country's ports — has threatened to break the alliance.

Ukraine this week threatened to sue Poland, Hungary, and Slovakia over their refusal to lift a ban on imports of Ukrainian agricultural products and Ukrainian President Volodymyr Zelenskyy insinuated that some European countries had feigned support for Ukraine, prompting anger in Warsaw.

Read more on the story here: One of Ukraine's strongest allies says it will no longer supply Kyiv with weapons

Zelenskyy calls for Russia to lose its UN veto power

Ukraine's President Zelenskyy on Wednesday called for Russia to lose its veto power within the U.N. Security Council.

In an address in New York, Zelenskyy said the move was a necessary step in bringing an end to the fighting in his country.

"It is impossible to stop the war because all efforts are vetoed by the aggressor," he said, adding that reforms of the council were long overdue.

"I know that the U.N. is capable of more. I'm confident that the U.N. Charter can actually work for the sake of peace and security globally. However, for this to happen, the years-long discussions and projects on U.N. reform must be translated into a viable process of UN reform," he said.

— Karen Gilchrist

Poland summons Ukraine ambassador over grain import dispute

Poland summoned the Ukrainian ambassador in the country Wednesday, as it hit back at President Volodymyr Zelenskyy's comments regarding its restrictions on Ukrainian agricultural imports.

"[Deputy Foreign Minister Pawel Jablonski] conveyed the Polish side's strong protest against the statements made by President V. Zelenskiy at the U.N. General Assembly yesterday, alleging that some EU countries feigned solidarity while indirectly supporting Russia," the foreign ministry said in a statement, as reported by Reuters.

Ukraine's foreign ministry spokesman Oleg Nikolenko said Ukraine had offered a "constructive path to resolve the grain issue."

Ukraine has heavily criticized Poland, Hungary and Slovakia for last week introducing bans on the domestic import of various Ukrainian agricultural products following the expiration of EU-led limitations on imports covering the three countries, as well as Romania and Bulgaria.

Products may transit the countries but not be sold there.

Land export routes have become crucial for Ukraine following the suspension of the Black Sea Grain Initiative, but farmers argue imports will overwhelm supply and cause a depression in prices if not restricted.

The EU had urged countries not to introduce divergent policies on the matter, as Ukraine agreed to introduce measures to prevent a supply glut, but national leaders argued this was insufficient.

Ukraine has filed a complaint with the World Trade Organization over the issue, thought to target Poland, Hungary and Slovakia.

Polish and Ukrainian officials have in turn suggested they may introduce further retaliatory trade curbs as the dispute has escalated.

Romania on Wednesday announced it would work with Ukraine on a plan to control exports.

— Jenni Reid

US plans big Ukraine aid announcement to coincide with Zelenskyy visit - official

U.S. President Joe Biden plans to announce a significant military aid package for Ukraine on Thursday to coincide with a visit to Washington by President Volodymyr Zelenskyy, a U.S. official said on Wednesday on condition of anonymity.

— Reuters

Read CNBC's previous live coverage here:

Zelenskyy calls for Russia to lose its UN veto power; Moscow’s losses rise in south