What could happen next if the USA rejects the Russian ultimatum?

Biden's Russia dealings may be the death knell of American credibility

Putin has declared today that he is “fed up” with the West: And when international law and the UN Charter interfere with them, they declare all this obsolete and unnecessary. And when something corresponds to their interests, they immediately refer to the norms of international law, the UN Charter, and international humanitarian rules. I’m fed up of such manipulations ”.