North Korea claimed Sunday that it had developed a hydrogen bomb to use with a long-range intercontinental ballistic missile (ICBM).
The claim by North Korea’s state media arm was first reported by South Korea’s Yonhap News.
The Korean Central News Agency said that that dictator Kim Jong-un inspected “an H-bomb to be loaded into [a] new ICBM” during a visit to the North’s Nuclear Weapons Institute. Photos accompanied the statement showed the purported hydrogen bomb being developed in a lab.
The explosive power of the “homemade” bomb is “adjustable from tens kiloton to hundreds kiloton,” the state run Korean Central News Agency said.
There was no immediate comment from the Pentagon or other U.S. officials. However, Director of National Intelligence Dan Coats told Congress in March that North Korea had developed the ability to put a nuclear warhead on a missile.
Experts have previously expressed skepticism about previous North Korean weapons claims. However, the announcement will raise already high worries in East Asia and in Washington that the North is closer to its goal of an arsenal of viable nuclear ICBMs that can reach the U.S. mainland.
In July, North Korea conducted two flight tests of an ICBM the Pentagon calls a KN-20. The July 28 test reached a height of 2,300 miles in space before returning to earth.
North Korea has conducted five nuclear tests since 2006, including two last year. The first of those tests involved what it claims to have been a hydrogen bomb and the second was its most powerful ever.
The key question is how far North Korea has gotten in efforts to consistently shrink down nuclear warheads so they can fit on long-range missiles.
South Korea’s main spy agency has previously asserted that it does not think Pyongyang currently has the ability to develop miniaturized nuclear weapons that can be mounted on ballistic missiles. Some experts think the North may have mastered this technology.
North Korea is thought to have a handful of rudimentary nuclear bombs and has spent decades trying to perfect a multistage, long-range missile to eventually carry smaller versions of those bombs.