SEOUL, South Korea (AP) — North Korea ratified a major defense treaty with Russia stipulating mutual military aid, the North’s state media reported Tuesday, as the U.S., South Korea and Ukraine say North Korea has sent thousands of troops to Russia to support its war against Ukraine.

The upper house of Russian parliament has ratified a treaty with North Korea envisioning mutual military assistance.

North Korea has ratified a landmark defence pact with Russia, state media reported Tuesday, deepening security cooperation that has seen Pyongyang send thousands of troops to help Moscow fight Ukraine.