North Korea has developed a new, more advanced hydrogen nuke that is small enough to be fitted on a new intercontinental ballistic missile, state media KCNA has claimed.
According to the KCNA report, North Korea's Nuclear Weapons Institute has created a “more developed nuke,” bringing about a “signal turn” in the country’s nuclear arsenal. Kim Jong-un, the country’s leader, inspected the new weapon during his visit to the nuclear facility.
https://www.rt.com/news/401850-korea-hydrogen-bomb-icbm/