North Korea could have tested some components of a hydrogen bomb in its Jan. 6 nuclear test, CNN reported Thursday, citing a U.S. official directly familiar with the latest U.S. assessment.

The assessment comes after careful examination of the latest intelligence analysis of the test data, CNN said.

CNN cited the unidentified official as saying that there may have been a partial, failed test of some type of components associated with a hydrogen bomb.

The test was conducted more than two times deeper underground than originally assessed, a depth consistent with what might be needed for a hydrogen bomb, but the size of the seismic event and other intelligence indicates it was not likely a fully functioning device, the report said.

The official was also quoted as saying that it is possible the North Koreans believe they conducted a full hydrogen bomb test, but the U.S. believes it was likely only some components, perhaps a detonator, that exploded.

North Korea claimed it successfully carried out its first hydrogen bomb test.

But the White House expressed strong skepticism, saying "initial analysis is not consistent" with the North's claims. U.S.

nuclear experts also have expressed doubts, saying its yield was too low for such an advanced bomb, way more powerful than conventional nuclear weapons. (Yonhap)