The United States has information that North Korea is preparing additional supplies of ballistic missiles to Russia, as well as long-range self-propelled artillery and multiple launch rocket systems (MLRS).

"For the Republic of Korea, these actions pose a serious threat, as North Korean troops are gaining combat experience, which could present additional security challenges in the region in the future," Defense Minister Rustem Umerov said following his visit to South Korea.

North Korea is expanding a weapons plant that manufactures missiles used by Russia against Ukraine, according to new research from a US-based think tank.