The display of disunity between the American and Ukrainian presidents risked emboldening Russia’s Vladimir Putin, whose terms for ending the war are unacceptable to Kyiv and U.S. allies in Europe.

A remarkable shouting match broke out in the Oval Office on Friday between President Donald Trump and his Ukrainian counterpart Volodymyr Zelensky, an extraordinarily fractious display that only underscored the deeply uncertain future of American assistance to Kyiv.