The fallout from the heated exchange sparked criticism from Ukraine-backing lawmakers as well as praise from Republican supporters of the U.S. president.

KYIV—A combative White House meeting has presented Ukraine with the prospect of fighting Russia without the support of its primary military backer through the first three years of the war. Now, the question is whether Europe has the firepower—and the political will—to help Ukraine hold off the Russians.

Ukrainian President Volodymyr Zelensky had traveled to Washington to sign a deal that would give the U.S. access to its mineral riches.