Analysts at the Institute for Science and International Security in Washington DC, an anti-proliferation think tank, say the country could have enough for a nuclear weapon this year.

The President warned against nuclear proliferation, saying nations - including his own - with weapon stockpiles must have 'the courage to escape the logic of fear and pursue a world without them'.

China has signed the Treaty on the Non-Proliferation of Nuclear Weapon and the Comprehensive Test Ban Treaty, and faithfully fulfilled the obligations set by the two treaties.