The evolving relationship of Kim Jong Un and Vladimir Putin sparks worries in Washington.

Kim is extending his stay in Russia's east.

Putin and Kim Jong Un attend a meeting at the Vostochny Cosmodrome in the Amur region, Russia.

Putin and Kim Jong Un pose for a photo during their meeting in Vladivostok, Russia, April 25, 2019.

North Korean leader Kim Jong Un departs Pyongyang, North Korea, to visit Russia, September 10, 2023.

North Korean leader Kim Jong Un, accompanied by government officials, departs Pyongyang, North Korea, to visit Russia.

North Korean leader Kim Jong Un shakes hands with Russian Natural Resources Minister Alexander Kozlov upon arrival in Khasan, Russia, September 12, 2023.