Hundreds of North Korean troops were likely transported by sea to Russia to fight in its war against Ukraine, satellite images have revealed, according to a new analysis from a US-based think tank shared exclusively with CNN.

North Korea appears to have sent more troops to Russia despite its soldiers suffering heavy casualties fighting on the front lines in Ukraine, South Korea’s main spy agency said Thursday. Seoul’s

North Korea has deployed thousands of troops to support Russian forces fighting in Ukraine, according to Ukrainian, U.S. and South Korean assessments, Pyongyang's first major involvement in a war since the 1950s.

Behavior in this war, not just of Moscow and Kyiv but of other states as well, has been conditioned by Russia’s possession and Ukraine’s lack of weapons of mass destruction. Russia holds the world’s largest arsenal of nuclear warheads,

Ukrainian troops holding positions in Kursk say the North Koreans have reappeared on the battlefield and become even more formidable foes.

Seoul reported on Thursday 27 February that Pyongyang had deployed additional armed forces to Russia. According to South Korean intelligence, additional troops have been sent to Russian soil and North Korean soldiers have once again been deployed on the front line in the Kursk region.