If Iran and world powers reach a nuclear deal, the United Nations Security Council will likely delay for at least a month action to lift UN nuclear sanctions on Tehran so US Congress can review the agreement, officials said.
Western officials, speaking on condition of anonymity, said it was an unwelcome development but politically necessary since Congress, dominated by Republicans critical of President Barack Obama's engagement with Iran, does not want the 15-member council to speak first, Reuters reported.
They said Congress would see that as prejudging any deal granting Iran sanctions relief in exchange for temporary constraints on its nuclear activities.
Iran wants the lifting of all US, UN and European Union sanctions to be simultaneous with the implementation of its commitments under the prospective deal.
Western officials have said they would need confirmation of Iranian compliance with the deal before easing sanctions, though delaying UN action for congressional review is a new element.
There is a June 30 deadline for an agreement between Iran, the United States and five other major powers. Western officials expect the talks to run into July.
Obama signed into law last month a measure giving Congress 30 days to review a deal before Obama could suspend US congressional sanctions, provided legislators receive the deal by July 8. After that, the review period would be 60 days.
Politically Unwise
The Security Council does not need congressional approval, but pre-empting Congress would be politically unwise, Western officials said. Still, they say a 60-day delay would be excessive.
"We can't wait too long because the Iranians could start going back on what they agreed," a senior western official said.
The UN nuclear agency, which is tasked with verifying Iran's compliance with the terms of an interim nuclear accord, has confirmed in its reports issued after the deal was signed in Geneva in late 2013 that Tehran has met all its commitments under the initial agreement. A UN vote would involve a Security Council resolution endorsing a deal and nullifying all previous sanctions resolutions.
Only the Security Council can lift UN sanctions.
Securing congressional approval of a deal will not be easy. A key US senator told Obama on Monday he was alarmed by reports of concessions by negotiators.
Iran and the six major powers (the US, Russia, China, France, Britain and Germany) agreed on the parameters of a long-term settlement in April.
Issues to be settled in the coming weeks include the speed of lifting sanctions and ways of monitoring compliance. Officials say there is no guarantee they will get an agreement.
