Wi Sung-lac, South Korea's national security chief, sets out for a visit to the US from Incheon International Airport on December 16, 2025. Photo: VCG

According to the Yonhap News, the South Korean military has initiated the formal process to acquire nuclear-powered submarines, a Navy document showed Wednesday, amid little progress in security talks with the US over Seoul's push for the project. Chinese experts warned that the move could intensify nuclear proliferation risks, undermine the global non-proliferation regime, and heighten the possibility of a regional arms race.

The South Korean Navy recently submitted the document to the Joint Chiefs of Staff (JCS) outlining the need for the program and specifying requirements, such as desired capabilities, the number of systems needed and projected deployment schedules, according to the Yonhap News.

The JCS is reviewing the Navy's proposal and is expected to hold a meeting later this month to finalize the requirements for the project, said the report.

South Korea and the US would have several discussions all at once in 2026 on implementing agreements reached in the summits between their leaders, National Security Adviser Wi Sung-lac claimed last year. In regard to civil uranium enrichment, spent fuel reprocessing and building nuclear-powered submarines, simultaneous talks would be held, he was quoted by the Yonhap News as saying in December of last year.

The US gave approval for South Korea to build nuclear-powered attack submarines and committed to working with Seoul to advance requirements for the project, including avenues to source fuel, under a joint fact sheet released after the summit between South Korea and the US. The summit document also commits the US to supporting Seoul in securing the right to enrich uranium and reprocess spent fuel, per Yonhap News on Wednesday. 

The South Korean military has reportedly been conducting a preliminary review to build at least four 5,000-ton-class nuclear-powered submarines after the mid-2030s, reported the Yonhap News on Wednesday.

Wang Yunfei, a Chinese military affairs expert, warned that South Korea's pursuit of nuclear-powered submarines could trigger further nuclear proliferation risks.

Wang told the Global Times on Wednesday that from a geographical perspective, the waters surrounding South Korea are dominated by relatively shallow seas, which are not well suited for the deployment of nuclear-powered submarines. Meanwhile, in terms of South Korea's actual defense needs, the range and strike capabilities of its land-based and air-based weapons are already sufficient to meet its primary defense requirements, making the development of nuclear-powered submarines appear unnecessary.

Against such a backdrop of limited necessity, the potential possession of nuclear-powered submarines could create the possibility of South Korea evolving into a state possessing strategic nuclear weapons, something the international community, including the United Nations, would not permit, as it would undermine geopolitical security.

Song Zhongping, a Chinese military affairs expert, told the Global Times that the US has made a bad precedent with the AUKUS nuclear-powered submarine program with Australia, and now a similar case is emerging for South Korea. The US' indulgence of allowing some of its allies to use its nuclear technologies and nuclear fuel will inevitably undermine the Treaty on the Non-Proliferation of Nuclear Weapons (NPT).

At the same time, given that Japan has also recently repeatedly promoted rhetoric advocating nuclear armament, this series of moves by South Korea and Japan could heighten the risk of a nuclear-powered submarine arms race and negatively affect regional security, Wang added.

According to the Sankei Shimbun, Japanese Defense Minister Shinjiro Koizumi claimed the necessity of introducing nuclear-powered submarines in November 2025, referring to the US's approval of South Korea's construction of such vessels.

Previously, in response to a related question on ROK and US side discussing nuclear-powered submarine issue, Chinese Foreign Ministry spokesperson Guo Jiakun said at a regular press conference in October 2025 that China noted the developments. China hopes that the ROK and the US will earnestly fulfill their nuclear non-proliferation obligations, and do what is conducive to regional peace and stability, not otherwise.

"China made clear its position on the relevant issue more than once. We hope the ROK and the US will prudently handle the matter," Chinese Foreign Ministry spokesperson Mao Ning said at a regular press conference on November 17, 2025.