South Korea's military is keeping a close watch on North Korea, the defense ministry said Monday, amid a report that the North may be ready to roll out a new submarine capable of launching ballistic missiles.

38 North, a US website monitoring North Korea, reported Friday that a dry dock at the North's Sinpo shipyard on its east coast has recently been repositioned along the submarine launch quay, saying the move could indicate that the North's new ballistic missile submarine "may be nearing completion or is ready to be rolled out and launched in the near future."

"We are thoroughly monitoring the situation under close coordination between South Korea-US intelligence authorities," ministry spokesperson Boo Seung-chan said during a regular press briefing. "We have no further information to give."

North Korea has been building a new submarine, which is believed to be a 3,000-ton one capable of carrying three submarine-launched ballistic missiles (SLBMs). Pyongyang first unveiled the new asset in July 2019.

On Thursday, North Korea launched two short-range ballistic missiles, the first in about a year, in violation of the UN Security Council resolutions and called it an exercise of the right to self-defense.

Earlier in the day, Jo Chol-su, director-general of the Department of International Organizations at the North's foreign ministry, accused the UN Security Council of applying a "double standard" over its recent missile launches and warned of a "countermeasure in kind" against "any attempt to infringe upon our right to self-defense." (Yonhap)