Russia has supplied advanced air defense missile systems to North Korea in return for Pyongyang sending troops to support its war in Ukraine, according to South Korean intelligence. Over 10,000 North Korean soldiers arrived in Russia in October, with many reportedly now engaged in combat on the front lines, particularly in the Kursk region.

North Korean soldiers have joined Russian units, including airborne and marine brigades, according to intelligence reports. Ukrainian President Volodymyr Zelenskyy suggested that up to 100,000 North Korean troops could eventually be deployed, though this number has not been confirmed. A top North Korean general is reportedly in Russia overseeing the deployment.

South Korea’s national security adviser Shin Wonsik said Russia has sent air defense systems and other equipment to strengthen North Korea’s defenses. Reports suggest that this may include components of the S-400 missile system, which has a range of 400 kilometers.

Russia has also reportedly provided economic support and technology to help North Korea’s struggling spy satellite program, though no specific agreements have been publicly disclosed.

North Korea has sent large quantities of weapons to Russia, including artillery shells, missiles, and other conventional arms. Since August 2023, over 13,000 containers of military supplies have reportedly been shipped to support Russian operations in Ukraine.

China, a key ally of North Korea, has avoided public comment on the growing ties but has signaled unease over the situation. Analysts suggest Beijing is wary of technology transfers that could increase regional instability.