The US is issuing conditional sanctions waivers for Iran today, though it cautioned they will not take effect until Tehran has curbed its nuclear programme as required under a nuclear deal reached in Vienna on July 14.

Senior US officials, who spoke on condition of anonymity, said that despite Washington’s move, actual implementation of the deal is likely several months away. They said the timing of nuclear-related sanctions relief will depend on the speed at which Iran takes the steps needed to enable the UN nuclear watchdog to confirm Tehran’s compliance.

“We cannot imagine it taking less than two months,” one of the US officials said. The “adoption day” for the deal, comes 90 days after Iran, the US, Britain, France, Germany, Russia and China reached an agreement under which most sanctions on Iran would be lifted in exchange for limits on Tehran’s nuclear activities.

Separately, Iran told the International Atomic Energy Agency (IAEA) yesterday that it would fulfil a commitment made under the deal to implement the Additional Protocol to its Comprehensive Safeguards Agreement, allowing UN nuclear inspectors more intrusive access to Iranian facilities.

In addition to Washington's conditional orders to suspend US nuclear-related sanctions, the US officials said the US, China and Iran are releasing a statement committing to the redesign and reconstruction of the Arak research reactor so that it does not produce plutonium.

The fate of the Arak reactor was one of the toughest sticking points in the nearly two years of negotiations that led to the July agreement.