Russia has gained approximately 6,000 square kilometres in the last two years while seriously depleting its armoury, so it is no wonder they are pleased to sit down now with Trump, as he offers them a way out while allowing them to save face.
Ukraine will have to sit down for talks but it's far from a given it will be accepted. With the Yanks pulling 40% of the funding Ukraine receives, it is hard to see them continuously holding out against Russia's human wave attacks long term.