President Biden detailed our efforts to prevent and respond to the invasion. If China provides material support to Russia it will have consequences for Ukrainian cities and civilians. The President supports a diplomatic solution to the crisis, according to the White House.

The White House said that Biden reiterated the U.S. policy on Taiwan and that the two presidents agreed to stay in communication.

A senior Biden administration official told reporters on a call Friday that the president made it clear that China should not support Moscow in its invasion. The official said that Biden outlined the view of the conflict and the actions and miscalculations of Putin. The official did not give details of the possible consequences or the reaction of the president.

The official described the call as "direct,substantive, and direct", but did not say whether China would aid Russia or not.

As Russia continues to escalate its attacks on the nation, the Biden-Xi meeting is a potential watershed moment for the relationship. The United Nations has confirmed nearly 2,000 civilian casualties.

The Chinese Embassy readout of the call did not mention Russia by name, but it did say theUkraine crisis is not something we want to see.

The events show that countries shouldn't meet on the battlefield. Peace and security are what the international community should treasure the most, because conflict and confrontation are not in anyone's interest. As permanent members of the UN Security Council and the world's two leading economies, we must not only guide the China-US relations forward along the right track, but also shoulder our share of international responsibilities and work for world peace and tranquility.

Last week, China announced a six point plan for preventing a widespread humanitarian crisis in Ukraine. The Chinese Ministry of Foreign Affairs said in a statement that the six points were reiterated by Xi during his call with Biden. The responsibility of the U.S. and its NATO allies was conveyed by Xi.

Ahead of the Biden-Xi meeting, Wendy Sherman said that the Chinese president had a choice to make: be a true leader on the world stage or siding with the Ukrainian people. She said Biden would urge Putin to end the war.

Sherman told MSNBC on Friday that he hoped he chose the right side of history.

As Russian troops bombard Ukrainian cities, Beijing tried to walk a delicate line. China has kept its trade relationship with Moscow while expressing concern about the deaths of civilians.

We are all very direct about what the responsibility is of the leader if he wants to be a true leader on the world stage. If he wants to sign up to the principles of the U.N. Charter, which he says he does, we will see. His future is with the United States and Europe. His future is not with Russia.

Over the weekend, Washington revealed intelligence and told reporters that Russia had requested economic and military assistance from China. The Chinese government responded to the request, though no details were given. Both Beijing and Moscow denied that request was made.

The report was contributed to by Jonathan Lemire.