Who is the "we" that should be negotiating? The US, EU, and NATO aren't parties to the conflict. Russia and Ukraine are free to negotiate at any time, and in fact have already held talks at several points during the conflict.

I assume thought, that you favor some sort of negotiated settlement. How much territory should Ukraine cede to Russia in exchange for peace? And what would prevent Russia from coming back and taking another slice in a few years? Remember they already did this once before in 2014.