The U.S. says there will be a "firm response" as Ukrainian forces holding ground in Russia's Kursk region now face North Korean troops "engaging in combat."

MOSCOW (Reuters) -Ukraine attacked Moscow on Sunday with at least 34 drones, the biggest drone strike on the Russian capital since the start of the war in 2022, forcing flights to be diverted from three of the city's major airports and injuring at least five people.

Russia attacked the Ukrainian capital Kyiv with a sophisticated combination of missiles and drones for the first time in 73 days on Wednesday, authorities reported, as the Pentagon said most of the North Korean troops sent to help Moscow’s war effort are fighting to drive Ukraine’s army off Russian soil in the Kursk border region.