President Donald Trump said Friday that he was unsure if he’d be able to end Russia’s war against Ukraine, a far cry from his promise to swiftly put a stop to the conflict that he made on the campaign trail.

President Trump said on Thursday that a phone call with President Vladimir V. Putin of Russia had not resulted in any movement toward ending the war in Ukraine, adding that he was “not happy” with the conflict grinding on. “I didn’t make any progress with him at all,” Mr. Trump told reporters.

Trump said he was "very unhappy" about his call with Putin a day earlier, given what he called the Russian leader's refusal to work on a ceasefire.