This photo, released by South Korea's defense ministry, shows Cho Chang-rae, left, Seoul's deputy defense minister for policy, shaking hands with Vipin Narang, acting U.S. assistant secretary of defense for space policy during talks in Seoul, June 10. Yonhap

South Korea and the United States signed joint nuclear deterrence guidelines in Washington on Thursday, in a milestone of bilateral endeavors to sharpen cooperation to counter evolving North Korean nuclear and missile threats.

Cho Chang-rae, Seoul's deputy defense minister for policy, and Vipin Narang, acting U.S. assistant secretary of defense for space policy, inked the "Guidelines for Nuclear Deterrence and Nuclear Operations on the Korean Peninsula."

The signing of the guidelines was a culmination of the bilateral Nuclear Consultative Group (NCG)'s efforts to ensure the credibility of America's "extended deterrence" commitment to South Korea in an integrated way that includes South Korea's conventional support for U.S. nuclear operations in a contingency.

Extended deterrence refers to a U.S. pledge to mobilize the full range of its military capabilities, including nuclear arms, to defend its ally.

"The guidelines provide principles and procedures designed to back efforts by the alliance's policy and military authorities to maintain effective nuclear deterrence policy and posture," Seoul's defense ministry said in a press release.

President Yoon Suk Yeol and U.S. President Joe Biden approved the update of the NCG in a joint statement, stressing that the guidelines document provides a "solid" foundation for enhancing the allies' extended deterrence cooperation in an integrated manner.

Yoon and Biden met on the margins of a North Atlantic Treaty Organization meeting in Washington.

The guidelines are expected to pave the way for a more systematic approach to nuclear deterrence at a time when Pyongyang is ratcheting up tensions with its continued tests of new, menacing weapons amid expectations that its burgeoning military cooperation with Russia could help its military programs.

The crafting of the guidelines was a key task of the NCG, a body established based on the Washington Declaration that Yoon and Biden adopted during their White House summit in April last year to bolster extended deterrence.

The declaration included a series of deterrence measures, including a U.S. pledge to enhance the "regular visibility" of strategic military assets to the Korean Peninsula -- an apparent move to help assuage deepening security concerns in South Korea and reaffirm Seoul's commitment to the non-nuclear proliferation regime. (Yonhap)