The angry exchange in Washington on Friday was the latest sign that Mr. Trump was pivoting American foreign policy away from traditional U.S. allies like Ukraine and Europe. It also illustrated the seriousness of his plans to quickly end the war in Ukraine, which could result in a deal that empowered Russia.

British Prime Minister Keir Starmer rallied his European counterparts Sunday to shore up their borders and throw their full weight behind Ukraine as he announced outlines of a plan to end Russia’s war.

British Prime Minister Keir Starmer said Sunday Europe was at a crossroads in history and must do the heavy lifting to defend itself as world leaders met in London to discuss ways of working together to stop Russia's war in Ukraine.