... Zelensky wants to negotiate on the matter of territorial concessions with Trump himself, ...

... while Moscow had "welcomed" the initial U.S. plan, "the situation will be fundamentally different" if the new version strays from understandings reached ...

So, more than a few details that need to be worked out?

... Russian Foreign Secretary Sergei Lavrov said Tuesday that while Moscow had "welcomed" the initial U.S. plan ...

Of course he may say that.

The initial "U.S." peace plan looked like it may have been translated from Russian by the google translate function.