Nuclear talks in Vienna
Nuclear talks in Vienna Reuters

Indirect talks between Tehran and Washington on reviving the 2015 Iran nuclear deal have come closer than ever to an agreement, but essential issues remain to be negotiated, the top Iranian negotiator said on Thursday, according to Reuters.

"We achieved good, tangible progress on the different issues .... we are closer than ever to an agreement but there are still essential issues under negotiations," Iranian Deputy Foreign Minister Abbas Araqchi was quoted as having told Al Jazeera television.

Araqchi said Iran's presidential election on Friday would have no effect on the negotiations and the Iranian negotiating team will continue the talks regardless of domestic policy.

"We want to make sure that what happened when Trump pulled out of the deal will not be repeated by any other American president in the future," Araqchi said on Thursday.

Iran has gradually scaled back its compliance with the 2015 deal in response to former US President Donald Trump’s withdrawal from the agreement in May of 2018.

Iran and six world powers have been negotiating in Vienna since April to work out steps for both sides to take

The sixth round of talks resumed on Saturday with the remaining parties to the deal - Iran, Russia, China, France, Britain, Germany and the European Union - meeting in the basement of a luxury hotel.

The US delegation to the talks is based in a hotel across the street as Iran refuses face-to-face meetings, noted Reuters.

Iran has insisted on a removal of all sanctions, while the Biden administration has insisted that some will remain if they were imposed over other concerns, including human rights and Iran's support for extremist movements.

US Secretary of State Antony Blinken recently said that "hundreds" of US sanctions will remain on Iran even if the United States rejoins the deal.

He has also warned that if Iran continues to violate the 2015 nuclear deal, the “breakout time” it needs to amass enough fissile material for a single nuclear weapon will shrink to weeks.