Richard Johnson is U.S. Deputy Assistant Secretary of Defense for Nuclear and Countering Weapons of Mass Destruction Policy. Courtesy of U.S. Department of Defense

A senior U.S. defense official visited Seoul's defense ministry Thursday to brief on its recently released key strategic documents that contain a warning to Pyongyang against a nuclear attack, officials here said Thursday.

Richard Johnson, deputy assistant secretary of defense for Nuclear and Countering Weapons of Mass Destruction Policy, met with Ha Dae-bong, director-general of the defense policy bureau, and other officials to explain this year's Nuclear Posture Review (NPR) and Missile Defense Review published last month, according to the ministry.

During the meeting, the U.S. side reaffirmed Washington will continue to provide extended deterrence for South Korea and utilize a full range of its available military capabilities, including nuclear, conventional, missile defense and other advanced non-nuclear ones, it added.

Extended deterrence refers to Washington's readiness to provide Seoul with all necessary options to deter aggression or provocation by North Korea.

The two sides also discussed ways to strengthen extended deterrence capabilities against Pyongyang's nuclear and missile threats, according to the ministry.

This year's NPR outlined that any nuclear attack by North Korea against the U.S. or its allies and partners will result in the end of its regime.

The ministry said U.S. officials gathered opinions from Seoul during the drafting process of the strategic reviews and visited the country in July prior to their release. (Yonhap)