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.

Amidst Russia’s conflict with Ukraine, North Korea’s support underscores an emerging, loose alliance with China, Iran, and Russia that challenges global stability. North Korea’s supply of arms and troops,

Russian President Vladimir Putin signed off on a landmark defense pact with North Korea amid reports Pyongyang has sent thousands of troops to fight Ukraine.

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

SEOUL, Nov 12 (Reuters) - North Korea has ratified a mutual defence treaty with Russia signed by the two countries' leaders in June, which calls for each side to come to the other's aid in case of an armed attack, state media KCNA said on Tuesday.

North Korean troops have begun engaging in combat operations alongside Russian forces, the U.S. State Department said on Tuesday, expressing concern that Russia had turned to North Korea for soldiers to fight in its war with Ukraine.

"Today I can confirm that over 10,000 (North Korean) soldiers have been sent to eastern Russia, and most of them have moved to the far western Kursk Oblast, where they have begun engaging in combat operations with Russian forces,

Former North Korean soldiers, operating under the name Defectors' Propaganda Corps, have delivered materials to Ukraine aimed at encouraging North Korean military personnel serving in the Russian army to desert.