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."

The attack ended a two-month pause in missile strikes on Kyiv, which had only been hit by Russian drones during that period.

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.

A doctor accused of criticizing the war in Ukraine in front of a patient was convicted Tuesday of spreading false information about the Russian military and sentenced to 5 and a half years in prison,

A doctor accused of criticizing Russia's war in Ukraine in front of a patient was convicted of spreading false information about the military and sentenced to 5 1/2 years in prison

The trilateral Freedom Edge exercise comes after North Korea launched a nuclear-capable missile and sent troops to Russia.

Kyiv, Ukraine - Approximately 8,000 North Korean troops have arrived in Russia’s western Kursk region, where they are expected to soon join the ongoing conflict against Ukraine, U.S. officials revealed on Thursday.

North Korea ratified a defense treaty with Russia, state media reported Tuesday, formally deepening military cooperation that has seen Pyongyang send thousands of troops to help Moscow in its war against Ukraine.