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.

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.

North Korea denounced joint military drills between the US and South Korea saying the South Korean Air Force’s recent bombing mistake shows the risk of the region unintentionally getting dragged into a new armed conflict.

North Korea on Wednesday continued to denounce joint military drills by South Korea and the United States, claiming South Korean jet fighters' latest accidental bombing of a village was an "ominous" sign that points to the danger of the exercise.

North Korea has issued a sharp rebuke over the major military exercise being carried out by the U.S. and its South Korean ally, labeling the training a "war rehearsal." Newsweek reached out to the Pentagon and the South Korean embassy in the U.