North Korea has unveiled for the first time what it says is a nuclear-powered submarine under construction, a weapons system that can pose a major security threat to South Korea and the US.

North Korea could be building a nuclear-powered submarine, possibly with Russian help, raising security concerns for the US and South Korea over its stealth attack capabilities

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.