U.S. Defense Secretary Lloyd Austin during a visit to South Korea Thursday said that North Korea's missile and weapons developments are increasingly destabilizing for regional security.

The United States calls on the North to engage in dialogue, Austin told a news conference after talks with his South Korean counterpart in Seoul, saying diplomacy is the best approach to pursue with North Korea, backed up by a credible deterrent.

Austin and U.S. Army Gen. Mark Milley, chair of the Joint Chiefs of Staff, held annual military talks with South Korean officials, covering an update to operational planning for a potential conflict with North Korea.

The United States has pledged to maintain the current level of U.S. troops in South Korea which stands at 28,500, South Korea's Defense Minister Suh Wook said after talks with Austin.

Suh also said the two sides made progress on meeting conditions for the transfer of wartime command control of their combined forces to South Korea.