North Korea unveils the completed hull of what it calls a nuclear submarine

Friday, December 26, 2025 -North Korea has publicly revealed the completed hull of what its government claims is its first nuclear‑powered submarine, a dramatic display of military advancement that has captured global attention. 

State media showed leader Kim Jong Un inspecting the massive 8,700‑ton vessel at a domestic shipyard, declaring the development a key part of the regime’s strategic deterrent and naval modernization plans. The submarine is described by Pyongyang as a “nuclear‑powered strategic guided missile submarine,” signaling intent to expand its sea‑based nuclear capabilities.

Analysts say the appearance of the fully welded hull suggests a significant jump in progress, with experts noting that such a stage often indicates core internal systems—including propulsion and possibly a reactor—may already be in place. 

Observers believe the design could allow the vessel to operate submerged for extended periods and potentially carry submarine‑launched missiles, raising concerns over stealth and survivability once deployed. While independent verification of the submarine’s capabilities remains limited, the hull reveal has intensified scrutiny from defense specialists in Seoul, Tokyo, and Washington.

The submarine unveiling also comes amid heightened regional tensions, with Pyongyang sharply criticizing South Korea’s plans to develop its own nuclear‑powered submarines in cooperation with the United States, calling those efforts a threat to its security. 

Experts warn that North Korea’s push for a sea‑based nuclear platform could complicate security calculations on the Korean Peninsula and prompt shifts in allied naval planning. As this strategic asset moves closer to potential sea trials, governments in East Asia and beyond are watching closely for what it could mean for the future of deterrence and regional military balance.