According to the channel, the U.S. intelligence watched the sub, when she stopped off the East coast of the DPRK. Further, the U.S. military noticed the activity of the North Korean Navy: they assume that vessels were sent in search of the submarine, reports BFM.

Sources have indicated to CNN that the U.S. not sure if drifting the submarine submerged or sank and lay on the bottom. However, they are confident that during the exercise the Navy of North Korea was any force majeure.

The situation on the Korean Peninsula worsened after the January 6 of this year, the fourth nuclear weapon test in North Korea and launch on 7 February of a satellite using a rocket that could be used for nuclear strike. The UN security Council in response, it has enacted the toughest package for the last 20 years of sanctions against North Korea.

About 300 thousand 17 thousand South Korean and American soldiers in South Korea participate since the beginning of this week in joint military exercises for the destruction of the North Korean leadership in the event of war, that North Korea already has reacted, threatening pre-emptive nuclear strike.