President Joe Biden on Wednesday warned that American troops could have to fight Russian troops if Congress prevents further and military aid being sent to Ukraine.
He demanded that lawmakers approve his request for tens of billions in military and economic assistance.
Republicans have said they are not willing to countenance another major package of aid unless the administration takes action on the southern border.
Biden said Republicans were handing Russian President Vladimir Putin a gift.
'This cannot wait,' he said in a televised address.
'Congress needs to pass supplemental funding for Ukraine before they break for the holiday resources as simple as that, frankly.'