On July 14, the United States and five other world powers signed a deal with Iran, which would end international economic sanctions on Tehran if it abandoned its nuclear weapons programme, claimed local media sources.

Tariq Fatemi, the prime minister's special adviser on foreign affairs, told a think-tank in Washington last week that Pakistan welcomed the deal because it would open the doors for economic cooperation with Iran, including the construction of a pipeline to bring natural gas for the energy-starved South Asian nation, reportedly.

Asked to comment on Mr Fatemi's statement, a State Department spokesman Mark Toner said the lifting of sanctions for commercial deals with Iran had not started yet.

"We don't consider Iran open for business yet, and there's no new sanctions relief beyond the very limited relief under the joint plan of action that's been in place since January 2014," he said. "When Iran meets its key nuclear steps and we get to implementation day, then there will be commensurate relief of nuclear-related sanctions."