Washington, Jul 7: Pakistan has the world's fastest-growing nuclear stockpile and it could achieve 150-200 warheads in a decade despite the political instability in the country, two top American atomic experts have said.

Pakistan is in the process of building two new plutonium production reactors and a new reprocessing facility to fabricate more nuclear weapons fuel, wrote nuclear experts Hans M Kristensen and Robert S Norris in the latest issue of Bulletin of Atomic Scientists.

In their paper ''Pakistan's nuclear forces, 2011'', the authors estimate that if Pakistan's expansion continues, its nuclear weapons stockpile could reach 150-200.

"Despite its political instability, Pakistan continues to steadily expand its nuclear capabilities and competencies; in fact, it has the world's fastest-growing nuclear stockpile," they wrote.

"We estimate that Pakistan has a nuclear weapons stockpile of 90-110 nuclear warheads, an increase from the estimated 70-90 warheads in 2009," the paper said.

"It is also developing new delivery systems. Enhancements to Pakistan's nuclear forces include a new nuclear capable medium-range ballistic missile, the development of two new nuclear-capable short-range ballistic missiles, and the development of two new nuclear-capable cruise missiles," they wrote.

"With four new delivery systems and two plutonium production reactors under development, however, the rate of Pakistan's stockpile growth may even increase over the next 10 years," they warned.

PTI