Putin not interested in any negotiation until he sees how this next offensive works out.
The same is true for the Ukrainians.
Arguably they may be locked into shelling for a couple more years in the east but that more or less works to the advantage of Ukraine, I would think.
Probably would work against Nato I would think, since Putin will try to up the game in some way if it drags on in order to create more American and EU pressure for Zelensky to find a settlement to avoid nuclear war and the general drag on the world if it goes on too long.