North Korean leader Kim Jong-un has appeared to suggest his country possesses a hydrogen bomb, in comments published on state media.
The country was "ready to detonate a self-reliant A-bomb and H-bomb", KCNA quoted him as saying.
If true, the development would mark a significant advancement in North Korean nuclear capabilities.
But the claim has not been independently verified and has drawn scepticism from experts.
Mr Kim made the remarks as he inspected a historical military site in the capital Pyongyang.
The work of his grandfather Kim Il-sung had turned North Korea into a "powerful nuclear weapons state ready to detonate a self-reliant A-bomb and H-bomb to reliably defend its sovereignty and the dignity of the nation", he is quoted as saying. READ MORE OF THIS STORY ON BBC ONLINE NEWS