North Korea said on Friday that it had used an underwater drone to practice launching a nuclear attack on an enemy seaport, saying that threats from the United States and its allies were forcing it to develop diverse means of carrying out nuclear strikes.
The drone was launched from the North’s east coast on Tuesday, the state-run Korean Central News Agency said. The report said it traveled underwater for more than 59 hours, reaching its target on Thursday afternoon, and that its “test warhead” — not an actual nuclear device — had detonated underwater. The target was not specified.
The drone, named Haeil, or tsunami, was designed to infiltrate enemy waters and “make a super-scale radioactive tsunami through underwater explosion” to destroy ships and ports, the report said. State media released photos of the North’s leader, Kim Jong-un, inspecting a torpedo-shaped vehicle in a warehouse and a similar vehicle traveling and detonating underwater.
There was no independent confirmation that the test had taken place. South Korea’s military, which usually confirms North Korea’s ballistic missile tests soon after they happen, said it was trying to determine whether the report was accurate, “keeping various possibilities in mind.”
Testing an underwater attack drone, let alone one capable of carrying a nuclear warhead, would be a first for the North.
North Korea has conducted a series of weapons tests in recent months, claiming that some of the missiles it launched could be equipped with nuclear warheads.
On Friday, North Korea made such a claim about strategic cruise missiles that it launched off its east coast on Wednesday. Test warheads on the missiles were detonated in midair to check their “nuclear explosion control devices and detonators,” state media said. Earlier in the week, state media had said that a ballistic missile test it conducted on Sunday also involved detonating a mock nuclear warhead.
Although North Korea has conducted six underground nuclear tests since 2016, it is unclear whether it has developed the kind of nuclear attack capabilities that its state media often says it has. The North claims to have nuclear warheads that are small and light enough to be mounted on drones, as well as on cruise and short-range missiles.
South Korea has said that it is carefully assessing the North’s evolving capabilities, which it says Mr. Kim’s government has often exaggerated.
“It’s hard to determine how much of the North Korean claim we can trust,” Kim Dong-yub, an expert on North Korean weapons at the University of North Korean Studies in Seoul, said of the reported drone test. But it would be wise not to underestimate the North, he said, noting that other nations had been developing various unmanned underwater weapons systems.
The North’s report said the drone could be towed by a ship and launched while at sea, which, if the drone were nuclear-capable, would extend the range of its nuclear arsenal. North Korea has been trying for years to build a submarine that could launch nuclear missiles far from its shores, but it has yet to deploy one.
Kim Jong-un, while observing weapons tests this week, called them proof that the North’s “unlimited” nuclear deterrent was being “bolstered up at a greater speed,” the state news media said. He also said that the United States and South Korea must stop their “reckless” joint military exercises, which the North calls rehearsals for an invasion.
The two allies on Thursday finished an 11-day joint exercise, their largest in years in terms of the number of troops involved. They are also in the middle of a separate exercise, involving a mock amphibious landing, that will continue until early April.
The North’s underwater drone test, if it took place, was held as a fleet of South Korean and American ships were joining the amphibious landing exercise, sailing toward Pohang, a port city on South Korea’s east coast. Next week, the American aircraft carrier Nimitz is scheduled to visit the larger port city of Busan.