North Korean state media has released images indicating significant progress on the construction of a nuclear-powered submarine, a move that could dramatically alter the strategic balance in the region.
Kim Inspects "Epoch-Making" Naval Project
On Thursday 25 December 2025, the official Korean Central News Agency (KCNA) published photographs showing leader Kim Jong Un inspecting what it described as an 8,700-ton-class nuclear-propelled submarine at a shipyard. The images reveal a largely completed hull, marking the first such visual update since March.
During the visit, Mr Kim declared that the submarine's completion would represent an "epoch-making" shift in bolstering the country's nuclear deterrent against perceived enemy threats. He framed the development as a necessary response to external pressures.
Condemnation of South Korea's Ambitions
Kim Jong Un used the occasion to launch a sharp critique of South Korea's own aspirations. He denounced Seoul's US-backed efforts to acquire a nuclear-powered submarine as an "offensive act" that gravely infringes on the North's security and maritime sovereignty.
He argued that South Korea's push further justifies the need to advance and nuclear-arm North Korea's navy. This rhetoric comes after South Korean President Lee Jae Myung sought US support for such technology during a November summit with former US President Donald Trump, pledging increased defence spending.
Expert Analysis and Regional Implications
While KCNA did not specify the visit's date, analysts suggest the near-complete hull indicates key components like the engine and reactor may already be installed. Moon Keun-sik, a submarine expert at Seoul's Hanyang University and former South Korean navy officer, stated that showing the entire vessel suggests it is nearly ready for launch and could undergo sea trials within months.
A nuclear-powered submarine, capable of prolonged stealth patrols and underwater missile launches, would significantly complicate detection efforts for neighbouring countries. This weapon was part of a list of advanced systems Kim Jong Un outlined at a 2021 party meeting, which also included:
- Solid-fuelled intercontinental ballistic missiles (ICBMs)
- Hypersonic weapons
- Spy satellites
North Korea has tested several of these systems recently and also unveiled a new destroyer intended to expand its nuclear forces' range.
Questions Over Technology and Rising Tensions
Doubts persist over whether sanctions-hit North Korea possesses the full resources and technology to build a functional nuclear submarine independently. Some experts speculate that Pyongyang's closer military ties with Russia, including support for Moscow's war in Ukraine, may have facilitated the transfer of key technologies.
While some suspect Russia could have provided a reactor, others believe North Korea likely developed its own, possibly with limited Russian assistance. Meanwhile, tensions on the Korean Peninsula remain high as Kim advances his nuclear weapons programme. His government has repeatedly dismissed calls from Washington and Seoul to revive denuclearisation talks, which collapsed after the failed 2019 summit with Donald Trump.
