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.

President Donald Trump and Vice President JD Vance had a heated exchange with Ukrainian President Volodymyr Zelenskyy in the Oval Office over the war in Ukraine, accusing him of not showing gratitude after he challenged Vance on the question of diplomacy with Russia’s Vladimir Putin.

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.