The North Korean leader, Kim Jong Un, was seen visiting a shipyard that constructs warships at an undisclosed location in a photo released by the North Korean government on March 8, 2025. North Korea revealed the construction of a nuclear-powered submarine for the first time, a system that could pose a significant security threat to South Korea and the US. State media released photos showing what was described as a “nuclear-powered strategic guided missile submarine,” during Kim Jong Un’s visits to major shipyards where warships are being built. Though details about the submarine were not provided by the Korean Central News Agency (KCNA), Kim was briefed on its construction. According to South Korean submarine expert Moon Keun-sik, the naval vessel appears to be a 6,000-ton or 7,000-ton class submarine capable of carrying about 10 missiles, including nuclear-capable weapons. Moon expressed concerns about the threat posed by such a submarine to South Korea and the US.
The introduction of a nuclear-powered submarine was part of a series of advanced weaponry that Kim had pledged to develop in response to what he perceived as escalating military threats from the US. In addition to the submarine, North Korea has been pursuing the development of solid-fueled intercontinental ballistic missiles, hypersonic weapons, spy satellites, and multi-warhead missiles, conducting various testing activities to acquire them.
The ability of North Korea to launch missiles from underwater is a cause for concern as it makes it challenging for its adversaries to detect such launches in advance. Questions have arisen about how North Korea, a country facing heavy sanctions and economic challenges, could acquire the necessary resources and technology to build nuclear-powered submarines. Moon speculated that North Korea might have received technological assistance from Russia in exchange for supplying conventional weapons and troops for Russia’s operations in Ukraine. He also suggested that the submarine could be launched for testing within the next one or two years before its actual deployment.
While North Korea possesses a significant number of diesel-powered submarines, mostly older models capable of launching torpedoes and mines but not missiles, the development of a nuclear-powered submarine represents a significant advancement in its naval capabilities. Previous claims by North Korea regarding the launch of a “tactical nuclear attack submarine” have been met with skepticism by foreign experts, who believed it was likely a diesel-powered submarine. North Korea has conducted several tests of underwater-launched ballistic missiles since 2016, primarily from a 2,000-ton class submarine with a single launch tube, which experts view as a test platform rather than an active operational submarine.
In the lead-up to their annual military drills, North Korea has escalated its rhetoric against the US and South Korea. Kim emphasized North Korea’s goal of modernizing its military capabilities during his visits to the shipyards.
The report from KCNA highlighted the importance of effectively utilizing both surface and underwater warships. It emphasized the necessity of ensuring that these powerful vessels fulfill their purpose in countering the aggressive gunboat diplomacy of hostile forces. To stay updated with the latest CNN news and newsletters, sign up for an account on CNN.com.
