I think there's an active conversation that is currently going on between President Zelenskyy and European allies. I heard in the media this morning that France and Poland are discussing a potential peacekeeping operation after the conflict.
All that is to say that I think the original comment of your question is that we actually don't really know where the U.S. administration is going to go on this. There's been a lot of talk. Part of it is probably election posturing, while part of it is trying to shape the ground. What we do know is that President-elect Trump has nominated the former national security adviser to the vice-president, General Kellogg, to be his Ukraine adviser.
What General Kellogg has said in the past in terms of the peace plan is it's freezing the battle lines, linking U.S. military aid to Kyiv's participation in peace talks, delaying Ukraine's NATO membership—putting it on pause to allow Russia to come to the negotiating table—and then lifting sanctions on Russia only after an agreeable peace has been agreed to by Russia.
All that is to say that it's a bit speculative. Your ultimate point is that if the U.S. were to withdraw its support in part or in whole, I certainly would see Ukraine looking to others to come forward. That certainly means European allies, but Canada too, given what we've been doing thus far.