North Korea Tests Two Types of Submarine-Launched Strategic Cruise Missiles in the Sea of Japan.

North Korea has tested two types of submarine-launched strategic cruise missiles in a significant demonstration of its expanding underwater strike capability, with state-run KCNA reporting that the weapons were fired into the East Sea on October 14 in Pyongyang’s first publicly disclosed underwater missile test since January 2024. South Korea’s Joint Chiefs of Staff assessed that one missile was launched vertically while the other was fired through a torpedo tube, suggesting North Korea is developing multiple strike options from a single submarine platform that could make its strategic missile force more flexible, dispersed, and difficult to track.

North Korea tested two types of submarine-launched strategic cruise missiles in the East Sea, signaling progress in integrating strategic strike weapons with its submarine force (Picture Source: KCNA)

North Korea has reported testing two different types of submarine-launched strategic cruise missiles, offering a potentially important indication of progress in integrating strategic strike weapons with its submarine force. The launches took place on October 14 in the Sea of Japan, known in the Koreas as the East Sea, according to the state-run Korean Central News Agency (KCNA). The activity represents North Korea's first publicly reported underwater missile-testing activity since January 2024.

KCNA said North Korea's Missile Administration tested two types of submarine-launched strategic cruise missiles (SLCMs) but did not specify their designations, ranges, flight profiles or other technical characteristics. According to the agency, “The test-fire aimed to examine the current mobilized posture of the underwater combat systems and contributed to getting the Navy skilled in performing its strategic missions.” Senior missile and naval officials reportedly observed the activity, while North Korean leader Kim Jong Un was not reported as attending. KCNA also said the launches did not adversely affect neighboring countries. The relatively operational language used in the announcement is notable because Pyongyang characterized the activity as an examination of readiness rather than publicly presenting either missile as a newly developed weapon.

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The submarine visible in imagery released by KCNA appears to be the Hero Kim Kun Ok, according to South Korean analysts, although North Korea did not officially identify the launch vessel. Unveiled in September 2023, the modified diesel-powered submarine was presented by Pyongyang as a “tactical nuclear attack submarine,” a description referring to its intended armament rather than nuclear propulsion. Imagery released when the vessel was unveiled showed at least ten missile-launch openings in addition to its torpedo tubes. If the Hero Kim Kun Ok was indeed used in the October test, the launches would represent its first publicly reported weapons tests and could indicate that North Korea has moved into a more advanced stage of integrating the vessel's combat and missile systems.

One of the most significant aspects of the test concerns the apparent use of two different launch architectures. South Korea's Joint Chiefs of Staff (JCS) said its forces tracked the missile activity from before launch through the cruise and terminal phases. A JCS spokesperson assessed that one type of cruise missile was fired from a vertical launch system, while the other was launched through a torpedo tube, according to reporting by Yonhap and Reuters. If accurate, the assessment suggests the event was not simply a test of two missile designs but also an examination of how different weapons can be employed from the same submarine platform. Yonhap additionally cited South Korean analysis indicating that the vertically launched weapon may have used one of the submarine's smaller vertical-launch tubes.

The precise identities of the two missiles nevertheless remain uncertain. KCNA did not name either weapon, meaning available identifications should be treated as analytical assessments rather than confirmed designations. One of the missiles may have been the Pulhwasal-3-31, a submarine-launched strategic cruise missile North Korea previously demonstrated in January 2024. Some South Korean analysts have raised the possibility that the latest test paired a longer-range SLCM associated with the Hwasal-2 family with a comparatively shorter Pulhwasal-3-31 variant. Independent analysis of the 2024 Pulhwasal-3-31 testing also concluded that imagery was consistent with a torpedo-tube launch, lending some technical plausibility to such an interpretation. However, neither the October imagery nor KCNA's announcement is sufficient to establish the missile identities definitively.

The apparent combination of vertical and torpedo-tube launches is potentially more consequential than the individual missile names. A submarine able to employ cruise missiles from different launch mechanisms could, in principle, provide greater flexibility in weapons configuration and complicate outside assessments of its loadout. Vertical launch systems can also offer advantages in launch sequencing and potentially permit faster employment of multiple weapons than reliance solely on torpedo tubes. Reuters cited defense analysts who noted that such systems could enable larger salvos and reduce warning time. At the same time, these potential advantages should not be confused with demonstrated operational capability: available evidence does not establish the Hero Kim Kun Ok's sustained patrol endurance, repeatable submerged-launch performance, salvo capacity, combat-ready missile inventory or survivability under operational conditions.

The test is better seen as a step in weapons-system integration than proof that North Korea already has a mature sea-based deterrent. The launches suggest progress in bringing the submarine, its combat systems and different missile types together, but key operational capabilities remain unproven. Long-duration patrols, repeated submerged launches and sustained weapons employment have yet to be publicly demonstrated. For now, the test points to a system moving closer to operational use rather than one whose full combat effectiveness has been established.

The October 14, 2026, test consequently appears to mark a potentially significant stage in North Korea's effort to develop a more diversified underwater strike capability. If subsequent evidence confirms that both a vertical launch system and a torpedo tube were used aboard the Hero Kim Kun Ok, the event would demonstrate meaningful progress in integrating different missile-launch methods within a single submarine platform. It would not, however, establish that North Korea has fielded a fully mature or continuously deployable sea-based strategic force. Further patrol activity, repeated weapons trials and possible future ballistic-missile launches will provide more reliable indicators of whether the submarine is progressing from a developmental platform toward sustained operational service.

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Written by Teoman S. Nicanci – Defense Analyst, Army Recognition Group

Teoman S. Nicanci holds degrees in Political Science, Comparative and International Politics, and International Relations and Diplomacy from leading Belgian universities, with research focused on Russian strategic behavior, defense technology, and modern warfare. He is a defense analyst at Army Recognition, specializing in the global defense industry, military armament, and emerging defense technologies.