North Korea said on Friday that its first submarine capable of launching nuclear missiles was now operational, a development that would give the country a new, harder-to-detect means of launching a nuclear strike.
The new “tactical nuclear attack submarine,” a remodeled Soviet-era vessel equipped with multiple launching tubes, was unveiled in a ceremony on Wednesday, state media reported. In a speech, Kim Jong-un, the North’s leader, vowed to similarly convert more of its existing submarine fleet, calling it “an urgent task of the times” to “arm the navy with nuclear weapons.”
But South Korea’s military expressed skepticism about the submarine on Friday, saying that it “doesn’t look capable of normal operation” and that there were signs of “deception and exaggeration” in the North’s report.
The United States and its allies have been closely watching the North’s attempts to develop a sub that could launch nuclear and other ballistic missiles. The capabilities of the one introduced this week, originally a Romeo-class Soviet submarine, are unknown; there is no evidence that North Korea has test-launched a missile from the vessel.
Photos released on Friday with the state media report show that the submarine has 10 vertical missile launch tubes of two different sizes, said Yang Uk, a weapons expert at the Asan Institute for Policy Studies in Seoul. It has an “abnormally large” missile launch deck for its size, as if the North wanted to show off its nuclear force, Mr. Yang said.
That structure “will limit the submarine’s underwater stealthiness and maneuverability,” Mr. Yang added. “Still, the design reflects Kim Jong-un’s policy of increasing his nuclear force ‘exponentially.’”
The submarine is powered by a diesel engine. That means that, unlike a nuclear-powered submarine, it would have to resurface frequently during a long-distance trip, like crossing the Pacific. For a distant adversary like the United States, that makes it more detectable, and less of a threat, than a nuclear-powered sub would be.
Nevertheless, it could potentially pose a new threat to the North’s regional adversaries, South Korea and Japan. Choi Il, a retired South Korean Navy submarine captain, said it was designed to carry shorter-range ballistic and cruise missiles that could reach those countries, not strategic ballistic missiles that could target the United States mainland.
“Our enemies will consider today’s launching a burden similar to the building of a new nuclear-powered submarine by us,” Mr. Kim said in his speech.
The new submarine — named Hero Kim Kun Ok, after a naval officer who fought in the Korean War — was unveiled days ahead of the 75th anniversary of the North’s founding, on Saturday. North Korea often celebrates its major holidays by staging a military parade or unveiling or testing new weapons.
Last month, the country tried and failed for a second time to put its first military reconnaissance satellite into orbit, a launch that analysts speculated was timed to generate propaganda for the Saturday holiday.
North Korea has dozens of small, diesel-powered submarines equipped with torpedoes, but before this week none had been capable of launching a ballistic missile. Since 2015, the North has been testing ballistic missiles designed for submarines, launching them from a submerged barge or a Soviet-era sub remodeled as an underwater test platform, with a single launch tube.
During recent military parades, the North has also displayed what looked like new, longer-range submarine-launched ballistic missiles. In 2019, state media released photos of Mr. Kim inspecting the submarine, then under construction, that was introduced this week.
The Hero Kim Kun Ok will serve as a standard for turning more old submarines into nuclear-capable models, Mr. Kim said in his speech. He also said his country had plans to build a nuclear-propelled submarine, as well as more advanced engines for its existing fleet.
It remains unclear how far North Korea is from its goal of building a fleet of submarines that can travel quietly and launch nuclear attacks. But American officials said this month that Mr. Kim planned to visit Russia soon for a meeting with President Vladimir V. Putin. That summit could lead to Russian technological support for the North’s nuclear and missile programs, in exchange for North Korean munitions, like artillery shells, that Russia needs for its war in Ukraine.
In addition to its submarine program, North Korea has been trying to make its ballistic missiles harder to detect and intercept, and it has tested cruise missiles and underwater drones that it said could carry nuclear warheads. An ability to launch nuclear strikes from underwater would be a major addition to the North’s growing nuclear arsenal.
In July, the United States docked a nuclear-capable ballistic missile submarine in South Korea for the first time in four decades, to show its commitment to defending its ally from North Korea.