Kim Jong-un’s inspection of an 8,700-ton nuclear-powered “strategic guided missile submarine,” as described by the state-run Korean Central News Agency (KCNA), framed shipbuilding as doctrine: a bid to accelerate the “nuclear weaponization of the navy” amid what he called a “negative security situation.”

KCNA photos show the submarine’s hull appearing largely completed, coated in anti-corrosion paint, inside an assembly hall; some images also show Kim accompanied by his daughter, Ju Ae.

Beyond the platform itself, KCNA said Kim reviewed the research-and-development status of “new secret underwater weapon” programs.

Analysts link this to the Haeil series of nuclear-armed unmanned underwater vehicles (UUVs), described as “nuclear attack drones.”

No public Haeil tests have been announced since early 2024, though the system appeared at a weapons exhibition earlier in 2025.

KCNA also tied the shipyard visit to broader force-development messaging.

On the same day as the submarine inspection, KCNA said Kim oversaw the successful test-firing of “new high-altitude, long-range” surface-to-air missiles the previous day, Dec. 24, 2025.

Taken together with Kim’s stated intent to reorganize naval forces, establish new units, and rapidly build additional surface and underwater warships with “advanced offensive” systems, the readout emphasizes simultaneous modernization across undersea, surface, and air-defense portfolios.

KCNA’s narrative explicitly set the program against external developments, condemning South Korea’s November 2025 plan to develop a nuclear-powered submarine with U.S. assistance as a “security threat” that would worsen regional instability and require countermeasures.

North Korea first publicly committed to building a nuclear-powered submarine in 2021, and initial construction photos were released in March 2025.