North Korean leader Kim Jong Un says his scientists have successfully miniaturised thermo-nuclear warheads to place on a ballistic missile and create a "true" deterrent, state media said Wednesday.
While Pyongyang has talked of success in mastering miniaturization before, this is the first time Kim has so explicitly claimed a breakthrough that experts see as a game-changing step for the North's nuclear capabilities.
Kim also stressed that the warheads were "thermo-nuclear" devices, echoing the North's claim that the fourth nuclear test it conducted in January was of a more powerful hydrogen bomb.