Pakistan, estimated to have the world's fastest-growing nuclear stockpile, could be building a new uranium enrichment complex according to commercial satellite imagery analysed by Western defence experts. The construction of a new site, based in the town of Kahuta some thirty kilometres east of Islamabad, provides fresh evidence of how Pakistan is seeking to boost its atomic arsenal — a goal which is inconsistent with the principles of the Nuclear Suppliers Group the country is seeking to join, said the analysis. The analysis was conducted by IHS Jane's Intelligence review using satellite images taken by Airbus Defence and Space on September 28, 2015 and then again on April 18, 2016.

Pakistan, which conducted its first nuclear tests in 1998 is believed to have around 120 nuclear weapons, more than India, Israel and North Korea.

A 2015 report written by scholars at the Carnegie Endowment for International Peace and the Stimson Center said Pakistan could increase its stockpile by 20 warheads a year and have the world's third largest in a decade.

"The area of interest is approximately 1.2 hectares and is located within the secure area of the Khan Research Laboratories (KRL), in the southwestern part of the complex," said the statement.