North Korean leader Kim Jong-un said on Thursday that his country has the capacity to launch a hydrogen bomb, the Korean Central News Agency reported. Kim made the comments during a tour of the Phyongchon Revolutionary Site, which commemorates the achievements of his father Kim Jong-il and grandfather Kim Il-sung.

The work of Kim Il-sung "turned the DPRK [Democratic People’s Republic of 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," Kim was quoted as saying.

A hydrogen bomb can produce a more powerful blast than an atomic bomb. International experts are sceptical of Kim's claim, even though North Korea successfully conducted underground nuclear tests in 2006, 2009 and 2013. If the hydrogen bomb claim is true, it would indicate significant advances in the country's pursuit of nuclear weapons, said Reuters.