[simpleman]

US is in no rush to negotiate to end the war because it is not the US that is losing to Russia. It is the Ukranians who are losing their lives, their territory to Russia, while the US politicians sit comfortably 6000 miles away.

Likewise Russia is not thinking of negotiating with Ukraine to end the war.

You only negotiate when you are losing. When you are on a winning streak, continue to win all the chips or as much as possible before calling  it a day. Russia will continue indefinitely until it has got all that it need to call mission accomplished.