Japan's foreign minister arrived in Kyiv on Saturday to discuss North Korea’s deepening military alliance with Russia, including the deployment of thousands of troops to support Moscow's war in Ukraine.

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."

Ukrainian officials expect a counteroffensive in western Russia to begin in the coming days as North Korea’s troops train with Russian forces.