Qatar's top diplomat in Tehran as Iran, US struggle to save 2015 pact

Qatar's foreign minister travelled to Tehran on Wednesday to help break a months-long impasse in indirect talks between Iran and the United States on reviving a 2015 nuclear pact.

The visit by Sheikh Mohammed bin Abdulrahman Al-Thani comes a week after EU-mediated indirect US-Iran talks in Doha that failed to break the deadlock stalling efforts to resurrect the nuclear agreement.

Iranian state media said Sheikh Mohammed and his Iranian counterpart Hossein Amirabdollahian will discuss "bilateral, regional and international issues" in Tehran.

Since last week, Iran has questioned US resolve to save the pact while Washington has said Tehran added new demands at the Doha talks. 

Iran's Amirabdollahian, however, said on Tuesday Tehran was ready to strike a "strong and durable" deal but Washington "must decide if it wants a deal or insists on sticking to its unilateral demands".

Under the 2015 deal, Iran curbed its uranium enrichment work, a potential pathway to nuclear weapons, in exchange for relief from economic sanctions. Iran says it seeks only civilian atomic energy.

But former US President Donald Trump pulled the United States out of the pact in 2018 and reimposed tough economic sanctions, prompting Tehran to breach many of the deal's nuclear limitations.

After almost a year of indirect negotiations in Vienna, the broad outline of a revived deal was agreed. But then talks broke down in March, largely over Tehran's demand that Washington remove its Revolutionary Guards from a US terrorism list. The United States refused, arguing this was outside the scope of reviving the agreement.

Other remaining obstacles to an agreement, Iranian and Western diplomats had said, include providing assurances that Washington will not quit the pact again and the International Atomic Energy Agency dropping its claims about Tehran's nuclear work.