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 major defence treaty with Russia that promises mutual military aid between the two nations, the North's state media has reported. It comes as the US, South Korea and Ukraine say North Korea has sent thousands of troops to Russia to support its war against Ukraine.