Ukraine has considerable leverage in upcoming negotiations with Russia—as long as the United States stands by Kyiv and adopts a negotiating strategy that creates real dilemmas for Moscow. U.S. support for Ukraine has been cast into doubt in recent weeks after a flurry of comments by Trump administration officials offering unilateral concessions to Moscow and criticizing Ukraine.

Russia on Tuesday demanded NATO scrap its 2008 promise to one day give Ukraine membership of the U.S.-led NATO military alliance and dismissed the idea that NATO member forces could be keepers of the peace under some sort of ceasefire deal.

Ukrainian President Volodymyr Zelenskyy said he would give up the presidency in exchange for peace and his country's acceptance into NATO, although it was not clear if he was actually considering stepping down.