Pakistan is a nuclear weapon state outside of the Nuclear Non-proliferation Treaty. It is believed to have about 120-130 nuclear weapons. Pakistan continues production of fissile materials for weapons.
As of the end of 2016, Pakistan had an accumulated stockpile estimated as about 280 kg of plutonium. This plutonium has been produced at four production reactors in Khushab. This estimate assumes that in 2016 Pakistan separated plutonium from the cooled spent fuel from Khushab-3 and Khushab-4 reactors, which began operating sometime in 2013 and in late 2014 or early 2015 respectively.
As of the end of 2016, Pakistan is estimated to have a stockpile of 3.4±0.4 tons of HEU and continues to produce HEU for its nuclear weapon program. Uncertainty about Pakistan's uranium resources, and the operating history and enrichment capacity of its centrifuge plant at Kahuta and a possible second plant at Gadwal (which may be dedicated to HEU production) limits the reliability of the estimate.