Russia launched its largest aerial assault of its three-year war on Ukraine overnight, targeting the capital and other regions with missiles and drones for a second night in a row, even as the two sides wrapped up a major prisoner exchange.

“A major prisoners swap was just completed between Russia and Ukraine. It will go into effect shortly,” Mr. Trump wrote on social media.

It was the largest attack of the war in terms of weapons fired, although other strikes have killed more people.