Pakistan has a nuclear weapon stockpile of 110 to 130 warheads, a rise from an estimated 90 to 110 in 2011, a US think-tank said on Wednesday.
"Pakistan has a nuclear weapons stockpile of 110 to 130 warheads, an increase from an estimated 90 to 110 warheads in 2011," said a report on 'Pakistani nuclear forces 2015' by the Bulletin of Atomic Scientists released during the ongoing visit of Pakistan Prime Minister Nawaz Sharif.
"With several delivery systems in development, four operating plutonium production reactors, and uranium facilities, the country's stockpile will likely increase over the next 10 years, but by how much will depend on many things," it said.
The report authored by Hans M Kristensen and Robert S Norris said the two key factors will be how many nuclear-capable launchers Pakistan plans to deploy, and how much India's nuclear arsenal grows.
Based on Pakistan's performance over the past 20 years and its current and anticipated weapons deployments, the authors estimate that its stockpile could realistically grow to 220 to 250 warheads by 2025, making it the world's fifth largest nuclear weapon state, the report reiterated.
Pakistan appears to have six types of currently operational nuclear-capable ballistic missiles, plus at least two more under development - the short-range Shaheen-1A and medium-range Shaheen-3.
Pakistan is also developing two new cruise missiles, the ground-launched Babur (Hatf-7) and the air-launched Ra'ad (Hatf-8), the report said.
According to the report there are signs that Pakistan is developing a nuclear weapon -- initially probably a nuclear-capable cruise missile -- for deployment on submarines.
In 2012, the Pakistani navy established Headquarters Naval Strategic Forces Command (NSFC) for the development and deployment of a sea-based strategic nuclear force.
The government said that this command would be the "custodian of the nation's second-strike capability" to "strengthen Pakistan's policy of Credible Minimum Deterrence and ensure regional stability".