Russia's debt default risk grows; Zelenskyy speaks to EU's Michel about more aid

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

Ukraine said Russia's assault on the eastern part of the country is continuing, with 38 towns hit in the Luhansk and Donetsk areas on Monday, damaging civilian infrastructure.

Ukraine remains at the top of the agenda at the World Economic Forum in Davos. Ukrainian President Volodymyr Zelenskyy addressed leaders of the business and political world at the summit via video link on Monday.

He said the world is at a "turning point" and must decide whether it would allow Russia's "brute force" to win. Russian politicians, business leaders and academics are absent from the event this year.

Ukrainian President Zelenskyy calls for stiffer sanctions against Russia at Davos
Ukrainian President Zelenskyy calls for stiffer sanctions against Russia at Davos

Meanwhile, a Russian soldier was sentenced to life in prison on Monday in the conflict's first war crimes trial. As the war drags on, the United Nations said that more than 6.5 million Ukrainians have become refugees.

Russia approves bill that would allow the appointment of new management for foreign companies that exit the country

A police officer patrols in front of the Russian State Duma and the building of the Hall of Columns, April 8, 2022.
Natalia Kolesnikova | Afp | Getty Images

Russia's parliament approved a bill that would allow the government to appoint new management of foreign companies that exited the country due to "anti-Russian sentiment in Europe and the U.S.," the Associated Press reported.

Many foreign companies have exited Russia after it invaded Ukraine, including McDonald's, which officially left after 32 years in the country.

After two more readings of the bill in parliament, it will go to the upper house and then to President Vladimir Putin for his approval, the AP reported.

Ukrainian Foreign Minister Dmytro Kuleba said the new law is another reason for foreign companies to leave Russia, according to the AP.

"It's the last chance to save not only your reputation but your property," he said in a statement, the AP reported.

— Chelsea Ong

Zelenskyy says Russia is putting everything it has into Donbas fight

Ukraine's President Volodymyr Zelenskyy speaks at a joint news conference, as Russia's attack on Ukraine continues, in Kyiv, Ukraine April 28, 2022.
Valentyn Ogirenko | Reuters

Ukrainian President Volodymyr Zelenskyy said Russia is using everything at its disposal in the fight for four cities in the eastern Donbas region.

"The situation in the Donbas now is very difficult," Zelenskyy said in his nightly address to the nation. "Practically the full might of the Russian army, whatever they have left, is being thrown at the offensive there. Liman, Popasna, Sievierodonetsk, Slaviansk – the occupiers want to destroy everything there."

A woman stands in front of a destroyed administration building in the city of Bakhmut in the eastern Ukranian region of Donbas, on May 25, 2022.
Aris Messinis | AFP | Getty Images

Zelenskyy said the Ukrainian army is fighting back, but "it will take time and a lot more effort by our people to overcome their advantage in the amount of equipment and weapons."

He told Ukrainians they should be proud of having held off Russia for three months in a war that many in Russia and the West expected to last three days.

Ukrainian servicemen get ready to move toward the frontline at a checkpoint near the city of Lysychansk in the eastern Ukranian region of Donbas, on May 23, 2022, amid Russian invasion of Ukraine.
Aris Messinis | AFP | Getty Images

— Associated Press

European Council president spoke with Zelenskyy about more military, humanitarian aid

European Council President Charles Michel talks during the joint press conference with European Commission President Ursula von der Leyen and Japanese Prime Minister Fumio Kishida following their meeting at the prime minister's office on May 12, 2022 in Tokyo, Japan.
Yoshikazu Tsuno | Getty Images

European Council President Charles Michel spoke with Ukrainian President Voldomyr Zelenskyy and reiterated the bloc's commitment to Ukraine's fight against Russia.

"As the war enters its fourth month, we discussed further humanitarian, financial and military assistance," Michel wrote in a tweet.

Michel added that the two discussed how the European Union could best support efforts to rebuild Ukrainian infrastructure destroyed by Russian forces.

"Also looked into global food security and efforts to unblock Ukraine's sea ports," Michel added.

— Amanda Macias

NATO chief warns Russia that an attack on one ally 'will trigger the full response from the whole alliance'

NATO Secretary General Jens Stoltenberg speaks during a press conference ahead of the alliance's Defence Ministers' meeting at the NATO headquarters in Brussels on March 15, 2022.
Kenzo Tribouillard | AFP | Getty Images

NATO Secretary-General Jens Stoltenberg said that while the 30-member military alliance has not put troops into Ukraine, a Russian attack "on one NATO ally will trigger the full response from the whole alliance."

"This is deterrence. The purpose is not to provoke conflict but to prevent conflict and preserve peace," Stoltenberg said at the World Economic Forum in Davos, Switzerland.

Since Russia invaded Ukraine in late February, NATO has increased its military presence in eastern parts of the alliance, Stoltenberg said.

"Now we have 40,000 troops in the NATO command. We have more naval, the air capabilities, especially in the eastern part of the alliance and we have 100,000 troops on heightened alert," he said. He added: "This is to send a very clear message to Moscow and leave no room for miscalculation or misunderstanding."

— Amanda Macias