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.

Everything we know about North Korea’s nuclear-powered submarine - Photos released by Pyongyang suggest new naval vessel could carry about 10 nuclear-capable missiles

The submarine could significantly escalate security concerns on the Korean peninsula and in the Taiwan Strait, experts say North Korea's construction of a nuclear-powered submarine could significantly escalate security concerns on the peninsula and in the Taiwan Strait,

North Korea has long vied for nuclear-powered submarines, which would allow it to fire missiles from underwater. Advanced detection of the weapons is difficult, making the country’s construction of the warships worrisome.

North Korea revealed a nuclear-powered submarine in construction. The vessel can carry about 10 missiles, including nuclear-capable weapons.

North Korean state media on Saturday released photographs of national leader Kim Jong Un inspecting progress on a “nuclear-powered strategic guided missile submarine.”

The news posted a photo showing the country's leader, Kim Jong-Un inspecting what seems to be part of the submarine.

SEOUL, South Korea — North Korea unveiled for the first time a nuclear-powered submarine under construction, a weapons system that can pose a major security threat to South Korea and the U.S.

Last week's accidental shelling of a South Korean village occurred less than 20 miles from the border of the nuclear-armed North.