U.S. and Iran chief negotiators to start nuclear talks in Qatar

The talks in the Qatari capital are the start of a process to "unblock" the Vienna talks

Chief negotiators from the United States and Iran were due to hold indirect talks in Qatar on Tuesday, bidding to overcome obstacles that have stalled attempts to revive a nuclear deal.

U.S. special envoy Robert Malley and Iran's Ali Bagheri headed to Doha after more than a year of European Union-mediated talks in Vienna on a return to the 2015 agreement.

The talks in the Qatari capital are the start of a process to "unblock" the Vienna talks, European Union foreign affairs spokesman Peter Stano said, adding they would start on Tuesday.

"We managed to unblock the process and we are going to move forward, and as a first step at this stage we have these proximity talks," he said in Brussels.

"That means indirect talks between Iran and the United States on finding the way how to move forward."

The deal aimed at curbing Iran's nuclear ambitions has been hanging by a thread since 2018, when then U.S. president Donald Trump unilaterally withdrew from it and began reimposing harsh economic sanctions on America's arch-enemy.

U.S. President Joe Biden's administration has sought to return to the agreement, saying it would be the best path ahead with the Islamic republic, although it has voiced growing pessimism in recent weeks.