who is "they"
Russia still has to agree to the cease fire. Until then, its not a cease fire.
US now will have to broker deal with Putin, who has CLEARLY stated unless all 4 regions are recognized as his, there is no use in negotiating. He wont come to talks.
So either US has told Ukraine this and Ukraine has agreed to ( highly skeptical ) OR US has not gotten an agreement from Ukraine on this and they will approach Putin anyway.
Again, Putin has publicly stated that for him to even consider coming to the negotiating table, those 4 regions will already be agreed upon as his. Not negotiable.
Further, the Kremlin has, for last 2 weeks, stated they will not agree to any ceasefire. Today even.
So now we will see if Putin loses face or Trump does. Someone not going to get what they wanted.