Ukraine said it struck a Russian air base on Saturday, while Russia continued to attack Ukraine with hundreds of drones overnight as part of a stepped-up bombing campaign that has dashed hopes for a breakthrough in efforts to end the more than 3-year-old war.

Russia pummeled Kyiv with the largest drone attack of the war, hours after President Donald Trump spoke to Russia's Vladimir Putin, officials said.

Russia launched 550 drones and missiles across Ukraine overnight in the largest aerial assault since the war began. The capital Kyiv was the primary target.