Washington: North Korea might have attempted to test components of a hydrogen bomb earlier this month, CNN reported on Thursday, citing an unnamed US official.
North Korea tested a nuclear device on January 6 that it said was a hydrogen bomb.
A US official directly familiar with the latest US assessment said the explosion may have been a partial, failed test of some type of components associated with a hydrogen bomb, CNN reported.
The size of the seismic event and other intelligence indicate it was not likely a fully functioning device, CNN said.
The official said it is possible the North Koreans believe they conducted a full hydrogen bomb test, but the US believes it was likely only some components, perhaps a detonator, that exploded, CNN reported.
US State Department spokesman Mark Toner told reporters earlier on Thursday that the United States still believes that Pyongyang did not test a hydrogen bomb.