The bombardment, which Ukrainian officials said mostly targeted Kyiv, came just a day before President Trump was expected to talk with President Vladimir V. Putin of Russia.

Russia has battered Ukraine overnight with its largest drone attack since the war began, Ukraine’s military said Sunday, as Moscow intensified its military assault despite holding direct peace talks with Kyiv Friday.

Trump has shifted U.S. rhetoric from supporting Ukraine toward accepting some of Moscow's narrative about the war. Kyiv and its European allies are working hard to persuade him that it is now Moscow that is holding up a truce.