Hegseth vows full US support for Korea’s nuclear submarine program

Defense Minister Ahn Gyu-back, right, shakes hands with U.S. Secretary of Defense Pete Hegseth after the 57th Security Consultative Meeting at the Ministry of National Defense in Yongsan District, Seoul, Tuesday. Joint Press Corps

U.S. Secretary of Defense Pete Hegseth said Tuesday that the United States will fully support Korea’s plan to develop nuclear-powered submarines, reaffirming U.S. President Donald Trump’s prior approval of the initiative.

“President Trump has approved this historic step, and I want to reaffirm that decision. As defense authorities, we will, of course, do our best to actively and fully support it,” Hegseth said during a joint press conference with Defense Minister Ahn Gyu-back after the 57th Security Consultative Meeting (SCM) at the Ministry of National Defense in Seoul.

He added, “There are other agencies involved, including the Department of State and the Department of Energy, and we will continue to coordinate closely with them. President Trump wants our allies to be strong, and the Republic of Korea is a model ally. Because of that, the president has been open to Korea acquiring greater and more advanced capabilities.”

The comment by Hegseth, who is also referred to by his government as the secretary of war, came after Trump said on social media last week, following a summit with President Lee Jae Myung, that he gave approval for Korea to build a nuclear submarine. He also wrote that the submarine would be built at Hanwha Philly Shipyard in the United States.

Under the nuclear energy agreement between the two nations, Washington's approval was critical because Seoul is prohibited from reprocessing spent nuclear fuel or using it for military purposes without U.S. consent.

Hegseth said he was convinced the nuclear submarine program would strengthen both Korea’s national defense and the bilateral alliance.

“Korea has world-class shipbuilding capabilities, and the United States looks forward to expanding cooperation not only in submarines but also in surface warfare," he said.

The secretary’s pledge marks a decisive acceleration of a long-sought and politically sensitive military goal for Seoul — and a major shift in U.S. policy toward nuclear naval technology transfer. For South Korea, the move could significantly strengthen its ability to deter North Korean aggression and counter Pyongyang’s submarine fleet. It may also stoke concern in Beijing and Moscow over a potential regional arms race.

While refraining from detailing technical aspects, Hegseth noted that future discussions would continue “in good faith.” He said both governments share confidence that ongoing consultations will lead to positive outcomes.

The secretary also cited progress in broadening the alliance’s defense-industrial cooperation. “For the first time in history, we agreed to demonstrate the ability to maintain and repair U.S. warships here in Korea,” he said.

Defense Minister Ahn Gyu-back answers questions from reporters during a joint press conference following the 57th Security Consultative Meeting at the Ministry of National Defense in Yongsan District, Seoul, Tuesday. At left is U.S. Secretary of Defense Pete Hegseth. Joint Press Corps

“This step harnesses Korea’s world-class shipbuilding strength and ensures that our most lethal capabilities remain ready to respond to any crisis. We also plan to expand this cooperation to ground equipment maintenance.”

During the press conference, Ahn dismissed speculation that South Korea may seek its own nuclear program. “There will never be nuclear weapons development in South Korea,” he said.

“Korea is a member of the Nuclear Nonproliferation Treaty, which prohibits us from possessing nuclear arms. The denuclearization of the Korean Peninsula remains an unwavering commitment.”

When asked if Seoul sought the redeployment of U.S. tactical nuclear weapons to the peninsula, Ahn responded, “Since South Korea cannot possess nuclear weapons, the Combined Nuclear Integration (CNI) system was established to integrate the U.S.’ nuclear capabilities with South Korea’s conventional forces.”

Ahn said the meeting reaffirmed “the solid military alliance and combined defense posture” between the two countries.

“Based on mutual trust and cooperation, we discussed ways to respond to evolving security challenges and to establish future-oriented and mutually beneficial defense cooperation,” he told reporters.

He added that the two sides agreed to enhance coordination in defense technology and research to ensure the most advanced readiness for both militaries.

The joint statement of this year’s SCM has not yet been released, as it has to reflect a joint fact sheet about the two nations' security and tariff issues, which is near completion. Once finalized, it is expected to outline follow-up measures for defense modernization and expanded cooperation within the alliance.

The SCM serves as the highest-level defense policy forum between Seoul and Washington. This year’s meeting came as the allies push to accelerate the transfer of wartime operational control from the U.S. to Korea and expand joint deterrence amid regional security shifts.