North Korea announced today that it had successfully carried out its first hydrogen bomb test, a development that, if confirmed, would mark a stunning step forward in its nuclear development.
''The republic's first hydrogen bomb test has been successfully performed at 10 am on January 6, 2016, based on the strategic determination of the Workers' Party,'' a state television news reader announced.
''With the perfect success of our historic H-bomb, we have joined the rank of advanced nuclear states,'' the announcer said, adding that the test was of a ''miniaturised'' device.
The surprise test was personally ordered by North Korean leader Kim Jong-Un and came just two days before his birthday.
Only last month, during remarks made during an inspection tour, Kim had suggested Pyongyang had already developed a hydrogen bomb, although the claim was greeted with scepticism by international experts.
A hydrogen, or thermonuclear, device uses fusion in a chain reaction that results in a far more powerful explosion than an atomic bomb. Its manufacture also involves far more complex technology.
''The latest test, completely based on our technology and our manpower, confirmed that our newly-developed technological resources are accurate and scientifically demonstrated the impact of our miniaturised H-bomb,'' the TV announcer said.
The announcement has left the international community scrambling to verify the accuracy of North Korea's claims.
Most experts had assumed Pyongyang was years from developing a thermonuclear bomb, while assessments were divided on how far it had gone in mastering the technology to miniaturise a device so as to fit on a ballistic missile.
While vowing to stick by a no-first use policy, Wednesday's statement said Pyongyang would continue to pursue advanced nuclear strike capability.
''As long as the vicious anti-North policy of the US persists, we will never stop development of our nuclear programme,'' the state TV said.