This is happening frequently, with leaders from all over the world. They are saying by actions that they have no respect for Biden and that talking to him is a waste of time. (since he does not know who he is talking to or why, and will forget the whole thing in an hour)
At this stage, America is isolated internationally and has zero clout to influence anyone about anything, except with money.
But, WE GOT RID OF TRUMP!! And that is the most important thing. <- i'm sure all the dead Ukranians and Russians would agree