SEOUL - North Korea has launched its first operational “tactical nuclear attack submarine” and assigned it to the fleet that patrols the waters between the Korean peninsula and Japan, state media said on Friday.

Submarine No. 841 – named Hero Kim Kun Ok after a North Korean historical figure – will be one of the main “underwater offensive means of the naval force”, North Korean leader Kim Jong Un said at the launch ceremony on Wednesday.

Analysts said the vessel appears to be a modified Soviet-era Romeo-class submarine, which the North acquired from China in the 1970s and began producing domestically.

Its design, with 10 launch tube hatches, showed it was most likely armed with ballistic missiles and cruise missiles, analysts said.

But such weapons will not add much value to the North’s more robust land-based nuclear forces, because its submarines may not survive as long during a war, said Mr Vann Van Diepen, a former US government weapons expert who works with the 38 North project in Washington.

“When this thing is field-deployed, it’s going to be quite vulnerable to allied anti-submarine warfare,” he said. “So I think from a sort of hard-headed military standpoint this doesn’t make a lot of sense.”

South Korea’s military said the submarine did not appear ready for normal operations and that there were signs the North was attempting to exaggerate its capabilities.

Seoul also condemned the submarine launch, saying Pyongyang was “squandering its scarce resources into its futile weapons development while disregarding (the) living difficulties of its people”.

At the launch ceremony, Mr Kim said arming the navy with nuclear weapons was an urgent task and promised more underwater and surface vessels equipped with tactical nuclear weapons for the naval forces, news agency KCNA reported.

“The submarine launching ceremony heralded the beginning of a new chapter for bolstering the naval force of the DPRK,” KCNA said, using the initials of the North’s official name, the Democratic People’s Republic of Korea.

North Korea plans to turn other existing submarines into nuclear-armed vessels and accelerate its push to eventually build nuclear-powered submarines, Mr Kim said.

“Achieving a rapid development of our naval forces... is a priority that cannot be delayed, given... the enemies’ recent aggressive moves and military acts,” he said in a speech, apparently referring to the United States and South Korea.

The North’s nuclear weapons and ballistic missile programmes are banned by United Nations Security Council resolutions, and the submarine launch drew condemnation from South Korea and Japan.

“North Korea’s military activity is posing a graver and more imminent threat to our country’s security than before,” Japanese Chief Cabinet Secretary Hirokazu Matsuno told a briefing.

Nuclear attack submarine

The designation as a “tactical” submarine suggests it does not carry submarine-launched ballistic missiles (SLBMs) that can reach the US mainland, but smaller, short-range SLBMs or submarine-launched cruise missiles (SLCMs) capable of striking South Korea, Japan or other regional targets, said Mr Choi Il, a retired South Korean submarine captain.

The rear of the submarine’s sail – the tower that juts out of the top of the hull – was expanded and 10 vertical launch tubes, four large and six small, were installed, most likely for SLBMs and SLCMs, he said.

North Korea has test-fired SLBMs and SLCMs.

It is unclear whether it has fully developed the miniaturised nuclear warheads needed for such missiles. Analysts say perfecting smaller warheads would most likely be a key goal if the North resumes nuclear testing.

North Korea has about 20 Romeo-class submarines powered by diesel-electric engines and obsolete by modern standards, with most other countries operating them only as training vessels.

Analysts first spotted signs that at least one new submarine was being built in 2016, and in 2019, state media showed Mr Kim inspecting a previously unreported submarine built under “his special attention” that would operate off the east coast.

State media at the time did not describe the submarine’s weapons systems or say where and when the inspection took place, but analysts said the apparent size of the new vessel indicated it was designed to carry missiles.

North Korea has a large submarine fleet, but only the experimental ballistic missile submarine 8.24 Yongung (Aug 24 Hero) is known to have fired a missile.

The launch ceremony comes as the North is set to mark the 75th anniversary of its founding on Saturday, and follows reports that Mr Kim plans to travel to Russia in September to meet President Vladimir Putin to discuss weapons supplies to Moscow.

South Korean President Yoon Suk-yeol on Thursday met Chinese Premier Li Qiang in Jakarta, and asked Beijing to do more as a UN Security Council member to address North Korea’s nuclear threat. REUTERS, AFP