The U.S. Department of Defense has rejected North Korea’s claim that the deployment of a nuclear-capable U.S. submarine to South Korea is a nuclear threat against the North, saying that the move is a prudent response to the regime’s escalatory behavior.

A Pentagon spokesperson issued the position on Thursday in reply to an inquiry by Yonhap News regarding a statement by the North Korean defense minister asserting that the deployment of U.S. strategic assets such as nuclear submarines in South Korea could meet the conditions for its use of nuclear weapons.

Pyongyang issued the statement after the U.S. Navy's Ohio-class ballistic missile submarine, the USS Kentucky, arrived in the southeastern port city of Busan on Tuesday, coinciding with the first session of the Nuclear Consultative Group established by South Korea and the U.S. 

The Pentagon spokesperson said that the actions taken by the U.S.-South Korea alliance under the Washington Declaration and through the Nuclear Consultative Group are a "prudent response" to the North’s "escalatory and dangerous" behavior, and further the allies’ goal of promoting peace and stability in the region.

The spokesperson said that unlike North Korea’s actions, efforts by South Korea and the U.S. to improve their defense posture and protect their people from the North’s nuclear threat do not violate UN Security Council resolutions.

Pentagon deputy press secretary Sabrina Singh also criticized Pyongyang’s statement as very dangerous, saying that the port call by the nuclear submarine was already planned during President Yoon Suk Yeol’s state visit to Washington.