Russia launched another attack on Ukraine's energy infrastructure on Thursday, leaving over a million households without power and forcing emergency power to be implemented nationwide.

"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.