President Joe Biden is slated to meet with Secretary of Defense Lloyd Austin, Deputy Secretary of Defense Kathleen Hicks, all eight members of the Joint Chiefs of Staff and U.S. combatant commanders at 4 p.m. E.T. in the Cabinet Room.

The White House meeting comes amid a new Russian offensive in the east and south of Ukraine and as the U.S. and its allies rush to transfer more weapons to the fight.

Following the meeting, Biden and the first lady will host a dinner for everyone and their spouses at 5:30 p.m. E.T. in the Blue Room.

— Amanda Macias

The United Nations says it has confirmed 2,224 civilian deaths and 2,897 injuries in Ukraine since Russia invaded its ex-Soviet neighbor on Feb. 24.

Of those killed, the U.N. has identified at least 42 girls and 61 boys, as well as 70 children whose gender is unknown.

The Office of the UN High Commissioner for Human Rights said Monday that the death toll in Ukraine is likely higher, citing delayed reporting due to the armed conflict.

The international body said most of the civilian casualties recorded were caused by the use of explosive weapons, including shelling from heavy artillery and multiple launch rocket systems, as well as missiles and airstrikes.

— Amanda Macias

Norway is sending 100 mistral air defense missiles to Ukraine, its defense ministry announced, describing the weapons as being phased out for the Norwegian military but still “modern and effective.”

“The mistral system has been used on deminers and corvettes. It is a type of air defence that the armed forces has planned to replace,” Defense Minister Bjørn Arild Gram said in a statement. “It will therefore not have a major impact on the national operational capability to donate the missiles.”

“The missile will be phased out by the Norwegian armed forces, but it is still a modern and effective weapon that will be of great benefit to Ukraine,” he said, adding that the weapons have already been sent from Norway.

— Natasha Turak

Russian troops are reportedly moving toward Ukraine’s southeastern city of Zaporizhzhia, its regional council said.

“The situation at the frontline suggests that the enemy is trying to advance in direction of Zaporizhzhia, but suffers losses and focuses its main efforts on maintaining the occupied frontiers,” the council said in a statement quoted by CNN.

“Russian troops continue to shell the positions of our troops and conduct offensive operations in the direction of Pokrovske – Huliaipole,” it added.

Zaporizhzhia is north of the embattled city of Mariupol, and is the destination point for a humanitarian corridor from Mariupol that was agreed for today between Russia and Ukraine.

The city is also home to Europe’s largest nuclear plant, which was captured by Russian forces early on in the invasion, along with the Zaporizhzhia thermal power station. Russian forces have already occupied areas south of Zaporizhzhia — Melitopol and Kherson — and the regional council claims that Russian forces are planning to hold “sham referendums” in the territories they occupy to validate their authority.

— Natasha Turak

President of the European Council Charles Michel has traveled to Kyiv via train in a show of support for Ukraine’s leadership. He was greeted by Olga Stefanishyna, Ukrainian deputy prime minister for European affairs and Euro-Atlantic integration, and is scheduled to meet with President Zelenskyy later today.

The visit comes just days after Ukraine completed its questionnaire for applying to join the European Union, the first step in the application to join the bloc. EU leaders have expressed optimism at the prospect of Ukraine potentially joining the group.

— Natasha Turak

A humanitarian corridor has been agreed to evacuate women, children and elderly people from Mariupol, Ukraine’s Deputy Prime Minister Iryna Vereshchuk said. The southeastern port city has been under constant Russian bombardment and cut off from basic necessities and aid since early March. Ukrainian officials hope to evacuate 6,000 civilians to the city of Zaporizhzhia via Berdyansk using 90 buses.

Humanitarian corridor agreements have often fallen apart due to renewed Russian shelling, Ukrainian officials say, and Tuesday had marked the third day of failure to agree on any such corridors.

More than 100,000 civilians still remain in Mariupol, officials say, down from a pre-war population of nearly half a million. The United Nations and Ukrainian President Volodymyr Zelenskyy have sounded the alarm over the severe humanitarian crisis in the city. A regional mayor described it as having been “wiped off the face of the earth” by Russian bombings.

— Natasha Turak

Major Serhiy Volyna, commander of Ukraine’s 36th Separate Marine Brigade, issued a desperate plea to world leaders in a Facebook video posted from the besieged city of Mariupol.

“This is our appeal to the world. This could be the last appeal of our lives. We are probably facing our last days, if not hours,” Volyna said, according to multiple translations. Russia has issued a new ultimatum, demanding the city surrender by 2:00 p.m. (7:00 a.m. ET) Moscow time, after Ukrainians refused to meet a surrender deadline last Sunday. Mariupol has been surrounded by Russian forces and largely cut off from electricity, water, food and heating since early March.

“The enemy is outnumbering us 10 to one. They have advantage in the air, in artillery, in their forces on land, in equipment and in tanks,” Volyna said, adding that his forces were “defending only one object” — the Azovstal steel plant where both military personnel and civilians were holed up, with reportedly hundreds wounded from Russian strikes. “We appeal and plead to all world leaders to help us,” he said.

The video was posted by Volyna from his personal Facebook page, not by the Azov unit. NBC has not independently verified the information.

In a prior post from Monday, Volyna wrote: “Our wounded die in unbearable torment daily as medicines, disinfectants, pain relief opportunities are long over.” He called for heavy weapons to be delivered to Ukrainian fighters in Mariupol.

The humanitarian situation in the eastern Ukrainian city, which had a pre-war population of around 500,000, is extremely dire, Ukrainian officials and humanitarian organizations say. At least 100,000 civilians still remain trapped there under heavy Russian shelling. Attempts to open humanitarian corridors to allow civilians to escape have consistently failed.

— Natasha Turak

China imported 30% less coal from Russia in March than last year, on worries of potential foreign sanctions and a decline in purchases of foreign coal, according to Reuters.

The news agency reported the country’s overall coal imports fell by 40% from last year as record domestic output and government price caps made overseas supply less attractive.

Reuters reported Chinese traders trimmed Russian coal imports in part because they had difficulty securing financing from state banks on edge about possible sanctions.

But a potential European Union ban of Russian coal could cause prices to plummet. Reuters reported Chinese traders have sought cheap cargos and looked to pay in yuan in order to bypass the international SWIFT transaction system.

— Chelsea Ong

Russia has set a new deadline for the surrender of the battered city of Mariupol by 2 p.m. Moscow time today (7:00 a.m. ET), saying in a statement early Wednesday morning that it would “once again” offer Ukraine the option “to stop fighting and lay down their weapons.”

An initial ultimatum demanding surrender by last Sunday, April 17, was ignored by Ukrainian forces in the city, who have pledged to “fight till the end.” Ukrainian defenders in the strategic port city are vastly outnumbered by Russian troops, who have surrounded it since early March, cutting it off from access to water, electricity, heat, internet, and most humanitarian aid.

Just 30 miles from the Russian border, Moscow views Mariupol as crucial territory that would give it a land corridor between the contested breakaway Donetsk and Luhansk People’s Republics, which Russia has recognized as independent, and the Crimean peninsula, which it annexed in 2014.

— Natasha Turak

Russia is trying to disrupt the movement of Ukrainian reinforcements and weaponry to the east of the country by attacking various cities, the British defense ministry said in an intelligence update.

But Russian air activity in northern Ukraine is “likely to remain low” following its withdrawal from the north of capital Kyiv, according to the ministry.

“However, there is still a risk of precision strikes against priority targets throughout Ukraine,” the U.K. ministry said.

Fighting in the eastern Donbas region is “intensifying” and Russia’s military build-up on Ukraine’s eastern border continues, the ministry said.

— Chelsea Ong

Russia is “blocking” efforts to organize humanitarian corridors in the strategic port city of Mariupol, Ukrainian President Volodymyr Zelenskyy said in his nightly video address.

“The situation in Mariupol remains unchanged — as severe as possible,” he said. Ukraine has not heard from Russia about the exchange offer, he added, referring to a proposal to trade detained pro-Russia Ukrainian opposition politician Viktor Medvedchuk for civilians and troops in the the battered port city.

He also said Russian forces are trying to carry out deportation or mobilization of Mariupol’s residents.

“The fate of at least tens of thousands of Mariupol residents who were previously relocated to Russian-controlled territory is unknown,” he added.

Zelenskyy also said that Russia has increased its intensity of fire “significantly” in the direction of Kharkiv —Ukraine’s second biggest city, as well as the Donbas and the Dnipropetrovsk region. The Donbas region is made up of the two pro-Russian self-declared “republics” of Luhansk and Donetsk

“They still consider ordinary housing infrastructure normal targets for them,” he said.

Ukraine previously said Russia’s full offensive against the Donbas region has begun, with a top official saying it is the “second phase” of the war.

Zelenskyy once again called for more military aid, urging countries not to delay sending any supplies.

“If we had access to all the weapons we need, which our partners have and which are comparable to the weapons used by the Russian Federation, we would have already ended this war,” he said.

— Chelsea Ong

The Russian troops now attacking eastern Ukraine are dealing with the same logistics and technical troubles that bedeviled them in the first phase of the war, a British government ministry said in an intelligence assessment Tuesday night.

Ukrainian troops have repulsed “numerous attempted advances” in the eastern Donbas region, according to the U.K. Ministry of Defence. Ukrainian President Volodymyr Zelenskyy said in a nightly video address on Monday that Moscow had begun striking Ukrainian targets in Donbas.

Donbas is a coal- and natural gas-rich part of eastern Ukraine that contains the Donestsk and Luhansk provinces.

“Russia’s ability to progress continues to be impacted by the environmental, logistical and technical challenges that have beset them so far, combined with the resilience of the highly-motivated Ukrainian armed forces,” the U.K. ministry said.

CNBC was unable to independently confirm the British assessment, though Russian troops are widely known to have redeployed to Donbas since retreating from Kyiv and other areas in the west.

The press office of the Russian Ministry of Defense was not immediately available to respond to CNBC’s request for comment.

— Ted Kemp