New Live Fire Test Highlights North Korea’s Improved Submarine Cruise Missile Strike Capabilities

The Korean People’s Army Navy has test-fired two types of submarine-launched strategic cruise missiles in waters off North Korea’s eastern coast, in a further demonstration of efforts to expand the capabilities of its naval forces and develop alternative means of delivering nuclear weapons. The tests took place on October 14, with the Korean Central News Agency reporting that the launches were intended to assess the readiness of the country’s underwater combat systems and improve the navy’s ability to carry out strategic missions. The description of the missiles as“strategic” indicated that Pyongyang intends the weapons to contribute to its nuclear deterrent, with  wider series of North Korean weapons tests intended to strengthen its ability to penetrate the missile defences of South Korea and its regional allies.

State media reported that the tests demonstrated the “high reliability, trustworthiness and ability of the war deterrents of the DPRK [Democratic People’s Republic of Korea].” The missiles’ designations, ranges, propulsion systems and other technical specifications were not disclosed, although photographs released alongside the announcement showed two different launch events, with one missile emerging vertically from the water in a plume of smoke and another appearing to leave the surface at an angle. This indicates that one was launched from a vertical launch cell, and the other from a torpedo tube. Although North Korea has for decades fielded one of the world’s two largest submarine fleets, which by many estimates has at times outnumbered that of the U.S. Navy, it only recently introduced cruise missile submarines into service, with these programs capitalising on major progress in developing cruise missile technologies. 

The submarine launch the cruise missiles was confirmed to be the conventionally powered warship the Hero Kim Kun Ok, which is thought to be serving as a testbed for a range of new weapons systems and other subsystems that will be integrated onto future nuclear powered attack submarines. The submarine was unveiled in September 2023 and described by its leadership as a tactical nuclear attack submarine. The vessel, designated hull number 841, is understood to be based on a modified Soviet-designed Romeo class diesel-electric submarine hull, rather than a locally built design. The October exercise represents the first publicly reported missile launch from the Hero Kim Kun Ok since its unveiling. South Korean analysts have suggested that the weapons could include the longer-range Hwasal-2 and the shorter-range Pulhwasal-3-31 cruise missiles, although these identifications remain unconfirmed. North Korea previously announced tests of Pulhwasal-3-31 submarine-launched cruise missiles in January 2024, when the weapons were reportedly fired from the smaller 8.24 Yongung experimental submarine.