N.Korea 'Ready to Launch New Missile Sub'

North Korea is building a new structure to launch submarines at the Sinpo shipyard, presumably for a new sub capable of carrying ballistic missiles.

State media unveiled the new 3,000-ton sub on July 23, when they reported that leader Kim Jong-un visited the shipyard.

The Middlebury Institute of International Studies, a U.S. think tank, and satellite operator Planet Labs spotted the launch structure on recent satellite images of the shipyard, according to NHK Friday.

Images from Sept. 3 show at least 13 pillar-like objects standing along a quay, with some vehicles moving around.

On Sept. 12, a large structure straddled the quay and water. And images from Sept. 19 show the structure covering almost the entire quay.

"The structure is now about 100 m long, which is much longer than what is used to build North Korea's conventional submarines," NHK said.

Once the sub is launched, the North could have the capability to clandestinely launch ballistic missiles from submarines at the U.S. mainland,.

Moon Keun-sik at the Korea Defense and Security Forum said, "The new North Korean sub will be capable of reaching an area around 2,000 km from the coast of the U.S. mainland, fire off a missile, and return to its home base."