The powerful sister of North Korean leader Kim Jong-un said on Thursday that the country’s nuclear-armed status was “absolute”, calling those hoping for its denuclearisation “idiots”. North Korea has legally enshrined its status as a nuclear weapons state, with its leadership declaring the country’s nuclear arsenal permanent and irreversible. US President Donald Trump recently said Pyongyang possessed 57 “very powerful” nuclear weapons, with Seoul putting the figure at between 80 and 120. “The...