A source close to the Iranian negotiating team in Vienna told IRNA that negotiations on reviving the Iran nuclear deal and lifting sanctions are pending receipt of a response from the US side.

The unnamed source added that the Vienna talks had made significant progress in the past week or so in light of Iran’s initiatives.

One of the steps Iran has taken to push the negotiations forward is agreeing on a roadmap with the UN nuclear watchdog to resolve all outstanding questions about the country’s nuclear program, the source stressed.

On the other hand, the source revealed that the US delegation in Vienna, which is taking part in indirect talks, is holding back from making political decisions, delaying the process of reaching a deal.

The US delegation is still in Vienna, awaiting political orders from Washington on the outstanding issues, according to the source, who added that a potential revival of the 2015 nuclear deal awaits a response to Iran's settlement proposals.

Ali Bagheri Kani, Iran's top nuclear negotiator, is scheduled to return to Austria on Wednesday morning after visiting Tehran on Tuesday.

The Vienna talks between Iran and the remaining JCPOA parties began in April on the assumption that the US, under the Joe Biden administration, is willing to reverse the so-called maximum pressure policy pursued by former President Donald Trump against Tehran.

Iran has stated that it will not accept anything less than the complete removal of all US sanctions in a verifiable manner. It also wants assurances that Washington will not withdraw from the agreement again.