North Korea has condemned a new agreement between South Korea and the United States to pursue nuclear-powered submarines, warning it could ignite a “nuclear domino phenomenon” and accelerate an arms race in the region.

The deal, unveiled last week by South Korean president Lee Jae Myung as part of a broader security and trade package with Washington, includes plans to advance nuclear-powered vessel development and expand Seoul’s authority over uranium enrichment and spent-fuel reprocessing.

In its first response, a commentary carried by the Korean Central News Agency called the submarine initiative a “dangerous attempt at confrontation” and a “serious development” that would destabilise the Asia-Pacific and undermine global nuclear control. Pyongyang also threatened “more justified and realistic countermeasures,” arguing the pact revealed the allies’ “confrontational intention.”

The warning comes as inter-Korean tensions remain high. North Korea announced in October that it had completed the ninth and final test of a ballistic engine, signalling that a full ICBM launch could follow. Meanwhile, Seoul has offered military talks to prevent border clashes—the first such proposal in seven years—and president Lee has urged broader dialogue without preconditions, a marked shift from the previous administration’s hard-line stance. Pyongyang has yet to respond.

Analysts say the North fears Seoul’s pursuit of nuclear-powered submarines could pave the way for a form of “semi-nuclear-weapon-state” status, potentially undermining prospects for renewed military talks.

China has also expressed concern. Dai Bing, Beijing’s ambassador to Seoul, cautioned that the pact goes beyond commercial cooperation and could affect both the global non-proliferation regime and stability on the Korean Peninsula.