North Korea's leader has claimed a quantum leap in his country's ability to wreak nuclear devastation by announcing that his regime is "ready to detonate" a hydrogen bomb.
A thermonuclear device of this kind is hundreds of times more powerful than the relatively crude atom bombs North Korea has tested underground.
The country set off nuclear devices in 2006, 2009 and 2013, which prompted United Nations Security Council sanctions banning trade and financing activities that aid its weapons programme.
Leader Kim Jong Un was quoted by the official KCNA news agency saying North Korea is a "powerful nuclear-weapons state ready to detonate self-reliant A-bomb and H-bomb to reliably defend its sovereignty".
The comments came as he toured the Phyongchon revolutionary site, which marks the feats of his father, who died in 2011, and his grandfather, North Korea's founder, Kim Il Sung.
