Moon, the submarine expert, said that North Korea may have received Russian technological assistance to build a nuclear reactor to be used in the submarine in return for supplying conventional weapons and troops to support Russia’s war efforts against Ukraine.

North Korea on March 8 released images of leader Kim Jong-un inspecting the construction of what it calls a “nuclear-powered strategic guided missile submarine,” marking its first public acknowledgment of the project.

The announcement came amid fears that Pyongyang may be receiving crucial military technology from Russia in return for sending troops and weapons for its war against Ukraine.