Russia-Ukraine updates: 2 US veterans who joined Ukrainian forces missing

U.S. Treasury Secretary Janet Yellen is pressuring China to convince Russia to end its war in Ukraine, citing the "special relationship" between the two countries.

“I fervently hope that China will make something positive of this relationship and help to end this war," Yellen said Wednesday during remarks to the Atlantic Council.

Despite a virtual meeting between President Joe Biden and Chinese President Xi Jinping back in March to discuss the crisis in Ukraine, China has remained neutral during the Russian invasion and has refused to openly condemn Russian President Vladimir Putin. U.S. officials have said that it does not appear China has assisted with Moscow’s requests for military and economic help.

"Going forward, it will be increasingly difficult to separate economic issues from broader considerations of national interest, including national security," Yellen said. "The world’s attitude towards China and its willingness to embrace further economic integration may well be affected by China’s reaction to our call for resolute action on Russia."

Yellen noted that Beijing claims to respect sovereignty and territorial integrity and said now is the time for China to put some weight behind their commitments.

"China cannot expect the global community to respect its appeals to the principles of sovereignty and territorial integrity in the future if does not respect these principles now when it counts," Yellen said.

China and India have continued to do business with Russia despite the international condemnation of Putin’s invasion and severe sanctions by the United States and its Western allies.

Yellen warned that any assistance to help Russia undermine or evade sanctions will not be taken lightly.

"Let me now say a few words to those countries who are currently sitting on the fence, perhaps seeing an opportunity to gain by preserving their relationship with Russia and backfilling the void left by others: Such motivations are short-sighted," Yellen said. "The future of our international order, both for peaceful security and economic prosperity, is at stake. This is an order that benefits us all. And let’s be clear, the unified coalition of sanctioning countries will not be indifferent to actions that undermine the sanctions we’ve put in place."

-ABC News' Justin Gomez

President Joe Biden officially announced Wednesday that his administration is "authorizing an additional $800 million in weapons, ammunition, and other security assistance to Ukraine."

Biden made the announcement in a statement released by the White House after he updated Ukrainian President Zelenskyy on the support during a phone call Wednesday morning.

Noting that Russia is preparing to focus its fight in the Donbas region of eastern Ukraine, Biden said the United States would continue to "provide Ukraine with the capabilities to defend itself."

"This new package of assistance will contain many of the highly effective weapons systems we have already provided and new capabilities tailored to the wider assault we expect Russia to launch in eastern Ukraine. These new capabilities include artillery systems, artillery rounds, and armored personnel carriers," Biden said.

He added, "I have also approved the transfer of additional helicopters. In addition, we continue to facilitate the transfer of significant capabilities from our Allies and partners around the world."

-ABC News' Molly Nagle

Russia is staging helicopters, artillery systems and troops in preparation for what is expected to be a renewed offensive in the Donbas region of eastern Ukraine, a senior U.S. defense official said Wednesday.

Russian forces have been using the cities of Belgorod and Valuyki in Russia near Ukraine's northeast border as primary sites to stage equipment and resupply troops, the official said. The United States is now seeing a third Russian town, Rovenki, also near the Ukraine northeast border, being used for that purpose.

The official said there's already signs that Russian forces are on the move south to the Donbas region.

"We continue to see units flowing into the northern Luhansk Oblast, that north part of the Donbas," the official said. "They're flowing in from Valuyki and from that town called Rovenki."

The long Russian convoy is heading south and, at last check, was near the city of Izium in eastern Ukraine, according to the official.

Other Russian troops to the south of Izium appear to be working to improve their mobility and firepower in the region, the official said.

"We've seen them try to erect a temporary bridge over a local river," the official said. "They're increasing their artillery in the area."

-ABC News' Matt Seyler

In a brief moment of joy amidst the brutality of war, rescuers in eastern Ukraine on Wednesday pulled a puppy alive from the rubble of a bombed building, authorities said.

The rescue unfolded in Mykhailivka in the Donetsk region, according to the Donetsk Regional Police.

Police released a video showing rescuers digging through the rubble with bare hands to reach the trapped pooch. Rescuers said they heard the puppy whining as they were picking through the rubble.

"Thanks to the boys for doing everything quickly and promptly here," said the dog’s owner while holding the trembling puppy in his arms