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.

Russia has bombarded Kyiv with the largest aerial attack since the beginning of its full-scale invasion of Ukraine in 2022.Overnight on Thursday, Moscow launched 539 drone and 11 missile strikes that struck nearly every district of the Ukrainian capital,

It was the latest in a series of almost weekly large-scale missile and drone attacks. President Trump said he “didn’t make any progress” with President Vladimir V. Putin of Russia.