US
Explosive yield of nuclear weapons 'increased exponentially' since Little Boy dropped on Hiroshima
US nuclear arsenal is about 20 times the size of China’s
US seeks to extend a 13-year arms embargo against Iran
Third such incident within week fuels speculation
Speaker advise Pakistan to carefully assess US-China tensions
Meeting discusses measures to bolster N Korea’s armed forces
United Kingdom has a stockpile of about 215 nuclear warheads, though about 120 are operationally available
As a meeting of the joint commission that oversees the deal is due to be held this month
Macron agrees to a costly modernisation of France's atomic arsenal
Rouhani dismisses idea, criticises Trump for always breaking promises