U.S. intel helped Ukraine sink Russian flagship Moskva, officials say; U.S. announces more humanitarian aid

This has been CNBC's live blog covering updates on the war in Ukraine. [Follow the latest updates here.]

Russian forces escalate their assault on the Azovstal steel plant
Russian forces escalate their assault on the Azovstal steel plant

Russia's progress in eastern and southern Ukraine is being closely monitored as its forces appear to have escalated assaults on those regions.

Having re-focused its attacks away from northern Ukraine and the capital Kyiv, Russian forces are now looking to take full control of the Donbas region in eastern Ukraine in order to create a land bridge from Russia to Crimea, territory it annexed in 2014.

In the latest update from the Ukrainian military, its spokesman said Russian forces "are focusing their efforts on blocking and trying to destroy Ukrainians units in the Azovstal" steelworks where soldiers and civilians have been holed up for up to two months.

"With the support of aircraft, the enemy resumed the offensive in order to take control of the plant," Ukraine said in its update Thursday morning.

Another 344 civilians were evacuated from the city and suburbs of the southern port city of Mariupol and are on the way to the Ukraine-controlled city of Zaporizhzhia, President Volodymyr Zelenskyy said in his nightly address.

Pentagon spokesman John Kirby said the Russians have made uneven progress in the Donbas region, following weeks of resupply and repositioning efforts. Nonetheless, the U.S. and its allies are rushing to send additional security assistance amid an intensified Russian assault in eastern and southern Ukraine.

George W. Bush and Zelenskyy meet virtually

Former President George W. Bush delivers a speech on Sept. 11, 2021. Bush met with Ukrainian President Volodymyr Zelenskyy virtually via an online video conference, where Zelenskyy invited Bush to visit Ukraine at his convenience.
Noah Riffe | Anadolu Agency | Getty Images

Former U.S. President George W. Bush and Ukrainian President Volodymyr Zelenskyy met via an online video conference, where Zelenskyy invited Bush to visit Ukraine.

Bush in turn conveyed his support for the president and the people of Ukraine.

"Your courage is very important for further success. If you continue to do what you do, you will always have our support if you continue to fight as you do now," he said, according to the Ukrainian president's office.

Bush also called Zelenskyy "the Winston Churchill of our time," according to a statment from the George W. Bush Presidential Center.

Zelenskyy expressed his appreciation for support from the U.S. and Americans.

"Americans are sincere, open-minded people, and I feel it. We have common values. I feel that it is from the heart," Zelenskyy said, according to the president's office.

— Chelsea Ong

U.S. intel helped Ukraine sink Russian flagship Moskva, officials say

The Russian missile cruiser Moskva was set afire and evacuated after a Ukrainian attack on the ship. Here the Moskva is shown off the coast of Syria in 2015.
Max Delany | AFP | Getty Images

Intelligence shared by the U.S. helped Ukraine sink the Russian cruiser Moskva, U.S. officials told NBC News, confirming an American role in perhaps the most embarrassing blow to Vladimir Putin's troubled invasion of Ukraine.

A guided-missile cruiser carrying a crew of 510, the Moskva was the flagship of Russia's Black Sea Fleet. It sank on April 14 after being struck by two Ukrainian Neptune anti-ship missiles, U.S. officials said. Moscow said the vessel sank after a fire. 

The attack happened after Ukrainian forces asked the Americans about a ship sailing in the Black Sea south of Odesa, U.S. officials told NBC News. The U.S. identified it as the Moskva, officials said, and helped confirm its location, after which the Ukrainians targeted the ship.

The U.S. did not know in advance that Ukraine was going to target the Moskva, officials said, and was not involved in the decision to strike. Maritime intelligence is shared with Ukraine to help it defend against attack from Russian ships, officials added.

Read the full story here.

— Ken Dilanian, Courtney Kube and Carol E. Lee, NBC News

Russia's war 'must end,' UN chief says he told Putin and Zelenskyy

"I was moved by the resilience and bravery of the people of Ukraine. My message to them is simple: We will not give up," tweeted UN Secretary-General Antonio Guterres, after he returned from a visit to Ukraine earlier this week, where he visited the Kyiv suburbs of Borodianka, Bucha and Irpin.
Anadolu Agency | Anadolu Agency | Getty Images

United Nations Secretary-General Antonio Guterres said he told both Ukrainian leader Volodymyr Zelenskyy and Russian President Vladimir Putin that the Kremlin's invasion must end for the sake of the entire world.

"Throughout my travels, I did not mince words," Guterres told the United Nations Security Council, following separate trips to the capitals of Russia and Ukraine.

"I said the same thing in Moscow as I did in Kyiv which is exactly what I have repeatedly expressed in New York. Namely that Russia's invasion of Ukraine is a violation of its territorial integrity and of the charter of the United Nations. It must end for the sake of the people of Ukraine, Russia, and the entire world," he said.

Guterres said that one goal of his trip was to broker the safe passageway of Ukrainians trapped in a steel plant in Mariupol. He said that so far, nearly 500 civilians have been evacuated after living under relentless shelling and scarce availability of food and water.

Guterres said that a third evacuation was underway but declined to elaborate in order to "avoid undermining possible success."

— Amanda Macias

UN says more evacuations are underway from bombarded Mariupol

The United Nations says a new "safe passage operation" is underway in and around the bombarded Ukrainian city of Mariupol.

Humanitarian spokesman Saviano Abreu tells The Associated Press the U.N. is working in