By Guy Faulconbridge, Steve Holland and Max Hunder MOSCOW/WASHINGTON/KYIV (Reuters) -U.S. President Donald Trump spoke to Russia's Vladimir Putin about Ukraine on Monday, after Vice President JD Vance said Washington could walk away from the peace process and conclude that "this is not our war".

Donald Trump and Russia's Vladimir Putin spoke over the phone for more than two hours on Monday, brainstorming, and possibly negotiating, what it would take for Moscow and Kyiv to agree to a fast, if not immediate ceasefire in Ukraine.