When the war is over, Ukraine is going to join NATO. And Putin is not capable of fighting against the combined NATO forces, even without the USA.
Ukraine on the other hand is not in a position to march into Moscow. So at some point a peace deal has to be made.
The war is currently in a stalemate and the frontlines are fortified. Any offensive is going to be very bloody. The Ukrainian people are going to decide if and how many lives they want to sacrifice to get back their land. Land is useless if the people are dead.