North Korea touts progress on nuclear-powered submarine

North Korea is showcasing what appears to be progress on a nuclear-powered submarine, with state media images revealing a largely completed hull.

Images released by North Korea's official Korean Central News Agency (KCNA) on Thursday showed leader Kim Jong Un visiting a shipyard to inspect the construction of what it said was an 8,700-ton-class nuclear-propelled submarine.

Mr Kim has said the completion of the submarine would mark an "epoch-making" change in strengthening the country's nuclear deterrent against what he described as enemy threats.

During the visit, Mr Kim denounced South Korea's US-backed efforts to acquire a nuclear-powered submarine as an "offensive act" that he said gravely infringes on the North's security and maritime sovereignty.

He added that South Korea's ambitions further underscore the need to advance and nuclear arm North Korea's navy.

KCNA did not specify when Kim visited the shipyard, but it was the first time North Korean state media had released images of the submarine since March, when coverage mostly showed the vessel's lower sections.

It was also not immediately clear how close North Korea is to finishing the submarine, though images showing an apparently near-complete hull suggest that key components, including the engine and possibly the reactor, have already been installed, according to experts.

"Showing the entire vessel now seems to indicate that most of the equipment has already been installed and it is just about ready to be launched into the water," said Moon Keun-sik, a submarine expert at Seoul's Hanyang University and a former officer in the South Korean navy.

He believes the submarine could be tested at sea within months.

A nuclear-powered submarine was among the advanced weapons Mr Kim outlined at a 2021 party meeting to counter what he described as growing US-led threats, alongside solid-fuelled ICBMs, which enable faster launches, hypersonic weapons, and spy satellites.

North Korea has since tested several of these systems and recently unveiled a new destroyer, which Mr Kim said would expand the range and preemptive strike capabilities of its nuclear forces.

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Analysts say a nuclear-powered submarine capable of prolonged stealth patrols and underwater missile launches would significantly complicate detection for neighbouring countries, though doubts remain over whether sanctions-hit North Korea has the resources and technology to build one.

Some experts suggest Pyongyang's closer ties with Russia - including military support for Moscow's war in Ukraine - may have helped it obtain key technologies.

While some suspect Russia could have provided a reactor, others argue North Korea likely developed its own, possibly with limited Russian assistance.

During a November summit with Donald Trump, South Korean President Lee Jae Myung sought US support for acquiring nuclear-powered submarines and pledged to boost defence spending to reduce America's burden.

Tensions on the Korean Peninsula have remained high as Mr Kim pushes forward with his nuclear weapons programme.

His government has repeatedly dismissed calls by Washington and Seoul to revive negotiations aimed at winding down its nuclear and missile programmes.

Negotiations collapsed in 2019 following a failed summit with Mr Trump during the US president's first term.

(c) Sky News 2025: North Korea touts progress on nuclear-powered submarine