Remarks by President Biden Before Marine One Departure,

[…] Q    Senator Tim Kaine, Democrats are talking about could U.S. troops be needed on the ground in or around Ukraine to stop an invasion.  Will you rule that out, or is that on the table?

The president:  That is not on the table.  What is not — they are not —

We have a moral obligation and a legal obligation to our NATO Allies, if they were to attack under Article Five.  It’s a sacred obligation.
That obligation does not extend to NATO — I mean, to Ukraine.  But it would depend upon what the rest of the NATO countries are willing to do as well.
But the idea the United States is going to unilaterally use force to confront Russia from invading Ukraine is not on — in the cards right now.  But what will happen is: There will be severe consequences that will have —

Q    Sir, you’ve known Vladimir Putin for years.  Are you confident that he got the message and knows this is different?

The president:  I am absolutely confident he got the message. Läs intervjun