North Korea Showcases Progress on Nuclear-Powered Submarine

Kim Jong Un hails vessel as “epoch-making” while condemning South Korea’s parallel ambitions

North Korea has revealed apparent progress in the construction of a nuclear-powered submarine, with newly released state media photos showing a largely completed hull. Leader Kim Jong Un inspected the vessel at a shipyard, describing it as a crucial step in modernizing and nuclear-arming the country’s navy.

The submarine, described by Pyongyang as an 8,700-ton-class nuclear-propelled vessel, is expected to be armed with nuclear weapons and designated as a “strategic guided missile submarine” or “strategic nuclear attack submarine.”

During his visit, Kim denounced South Korea’s own efforts to acquire nuclear-powered submarines—backed by U.S. President Donald Trump—as an “offensive act” that violates North Korea’s security and maritime sovereignty. He claimed the completion of the submarine would mark an “epoch-making” advance in strengthening the North’s nuclear deterrent.

Photos released by the Korean Central News Agency showed Kim inspecting the burgundy-colored vessel inside an assembly hall, accompanied by senior officials and his daughter. Analysts noted that the display of a nearly complete hull suggests that core components, including the engine and possibly the reactor, may already be installed, raising the possibility of sea trials within months.

A nuclear-powered submarine has long been one of Kim’s stated military goals, alongside solid-fueled intercontinental ballistic missiles, hypersonic weapons, spy satellites, and multi-warhead missiles. North Korea has already unveiled a new naval destroyer and conducted multiple weapons tests, underscoring its push to expand nuclear strike capabilities.

Experts remain divided on how North Korea, under heavy sanctions, has acquired the resources and technology for such a project. Some point to its growing alignment with Russia, suggesting Pyongyang may have received technological assistance in exchange for military support in Ukraine.

Meanwhile, South Korea has sought U.S. backing for its own nuclear-powered submarine program. Trump has indicated openness to sharing technology, though details on construction, fuel supply, and reactor development remain unclear.

The developments come amid escalating tensions on the Korean Peninsula, as North Korea accelerates its nuclear program and deepens ties with Moscow, while dismissing calls from Washington and Seoul to resume denuclearization talks.

Strategic Analysis: North Korea’s Nuclear Submarine Ambitions

Regional security implications of Pyongyang’s naval modernization and Seoul’s parallel ambitions

1. North Korea’s Strategic Messaging
• The unveiling of a nearly completed 8,700-ton nuclear-powered submarine signals Pyongyang’s intent to project strength and deterrence.
• Kim Jong Un frames the submarine as an “epoch-making” milestone, linking naval modernization directly to nuclear deterrence.
• By publicizing progress, North Korea seeks to demonstrate resilience despite sanctions and reinforce its alignment with Russia.

2. Technological Feasibility and Russian Factor

• Building a nuclear-powered submarine requires advanced reactor technology, metallurgy, and stealth systems.
• Analysts debate whether North Korea has indigenous reactor design capability or has received technical assistance from Russia.
• Recent military cooperation with Moscow, including troop and equipment transfers to support Russia’s war in Ukraine, raises the likelihood of technology exchanges.

3. South Korea’s Parallel Ambitions
• Seoul has openly pursued nuclear-powered submarine technology, with U.S. backing under President Trump.
• South Korea’s plan reflects both regional deterrence needs and a desire to reduce reliance on U.S. extended deterrence.
• Pyongyang interprets Seoul’s ambitions as an “offensive act”, using them to justify its own accelerated nuclear naval program.

4. Strategic Balance in Northeast Asia
• A nuclear-powered submarine would allow North Korea to launch missiles stealthily from underwater, complicating detection and interception.
• If operational, such a platform would shift the deterrence equation, forcing South Korea, Japan, and the U.S. to expand anti-submarine warfare (ASW) capabilities.
• The arms race dynamic is evident: Pyongyang’s progress fuels Seoul’s ambitions, while U.S. support for South Korea intensifies North Korea’s threat perception.

5. Broader Geopolitical Context
• North Korea’s submarine project is part of a 2021 wish list of advanced weapons: hypersonic missiles, spy satellites, and multi-warhead ICBMs.
• The submarine complements Pyongyang’s new destroyer and missile tests, expanding its maritime strike range.
• Alignment with Russia provides political cover and potential technical aid, while isolating North Korea further from Western-led diplomacy.

Conclusion

North Korea’s nuclear submarine program is not just a military project—it is a strategic signal aimed at reshaping deterrence dynamics in Northeast Asia. By pairing naval modernization with nuclear armament, Pyongyang seeks to offset South Korea’s ambitions and deepen its partnership with Russia. The result is a heightened arms race that challenges regional stability and complicates U.S. and allied defense planning.

Source: Seul, South Korea, AP & ©XAirForces News, 25 December 2025

Photo: Kim Jong Un, North Korea’s leader, inspected the country’s nuclear-powered submarine, said to weigh 8,700 tons, while describing Seoul’s plan to develop nuclear-powered submarines as ‘an offensive act,’ according to KCNA. (Photo by ©KCNA Service via AP)

Editor: Mark Choi (Asian ©XAirForces Editor from South Korea)

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North Korea Showcases Progress on Nuclear-Powered Submarine


(25.12.2025)