Washington: China cannot cover Russia for the impact caused by the US and European sanctions, said White House spokesperson Jen Psaki on Thursday.

"[China] they cannot cover what the impact of the sanctions that have been announced in coordination with Europe would, how they would impact Russia," Psaki said during a press briefing.

This comes at a time when Russian President Vladimir Putin recognized the independence of Ukraine breakaway regions following which Biden has imposed "severe" sanctions on Russia.

When asked whether the US was prepared to accept refugees from Ukraine, Psaki said, "We are, but we certainly expect that most, if not the majority, will want to go to Europe in neighbouring countries."

Furthermore, she said, "We are in conversations with Congress, and I mentioned the President spoke with leaders just earlier this afternoon. I don't have an exact number, but those are ongoing conversations about what needs the Ukrainians have on the ground in a variety of categories: security, humanitarian, other economic assistance."

Speaking on any nuclear threats from Russia, Psaky said, "[W]e don't see any increased threat in that regard at this point in time."

Biden on Thursday said that the US will introduce a new wave of sanctions against Russia in a broad effort to isolate Moscow from the global economy.

The new package of sanctions aims to cut Russia off from the US financial markets and includes freezing the assets of four major Russian banks, including VTB Bank, the nation's second-biggest bank, Biden said Thursday.

"Today, I'm authorizing additional strong sanctions and new limitations on what can be exported to Russia," Biden said. "This is going to impose a severe cost on the Russian economy both immediately and over time."

"I just spoke with the G-7 leaders this morning," Biden said Thursday afternoon. "And we're in full and total agreement: We will limit Russia's ability to do business in dollars, euros, pounds, and yen to be part of the global economy. We'll limit their ability to do that."