South Korea and the United States signed joint guidelines to respond to North Korean nuclear attacks, including expanding the deployment of U.S. strategic assets on the Korean Peninsula to a permanent level.

The agreement comes as Seoul and Washington's Nuclear Consultative Group(NCG) heads, deputy defense minister for policy Cho Chang-rae and acting U.S. assistant secretary of defense for space policy Vipin Narang on Thursday local time, signed the "South Korea-U.S. Guidelines for Nuclear Deterrence and Nuclear Operations on the Korean Peninsula" at the Pentagon.

The U.S. Department of Defense explained that the guidelines provide principles and procedures to aid the alliance's policy and military authorities in maintaining effective nuclear deterrence policies and postures.

The main contents of the joint guidelines include the two allies substantially strengthening the alliance's posture and capabilities by conducting exercises and training by applying the Conventional-Nuclear Integration plan.

Seoul's defense ministry said that the signing of the guidelines was a confirmation of U.S. nuclear assets being deployed to missions on the Korean Peninsula in times of both war and peace to deter and respond to North Korea's advancing nuclear threats.