Russia's envoy to talks on reviving Iran's 2015 nuclear deal said on Friday they had resumed in a "serious" atmosphere even as few expect a breakthrough compromise while Tehran's disputed uranium enrichment program surges forward.
Indirect talks between Tehran and Washington restarted in Vienna on Thursday with a meeting between the Islamic Republic's chief nuclear negotiator Ali Bagheri Kani and European Union coordinator Enrique Mora.
Reuters, citing one Iranian and one European official, reported in June that Tehran had dropped a major stumbling block - its demand for the removal of its Revolutionary Guards from a U.S. sanctions list.
A senior Iranian official suggested that the issue might not be a sticking point anymore, telling Reuters on Thursday: "We have our own suggestions that will be discussed in the Vienna talks, such as lifting sanctions on the Guards gradually."
After meeting Bagheri Kani on Friday, Russian envoy Mikhail Ulyanov was quoted by Iran's state news agency IRNA as saying that reaching the finish line "may not be so easy, and time will tell whether we will succeed or not.
"But in general, the atmosphere of the talks is serious."
White House national security spokesman John Kirby said on Thursday that the negotiations were "pretty much complete at this point".
Bagheri Kani put the onus on the White House to compromise, tweeting that the United States should "show maturity & act responsibly."
The European parties to the deal urged Iran in a statement "not to make unrealistic demands outside the scope of the JCPoA (nuclear deal), including on IAEA safeguards”.
"The text is on the table. There will be no re-opening of negotiations. Iran must now decide to conclude the deal while this is still possible," the statement said.
Foreign Minister Hossein Amirabdollahian said on Friday that for Tehran's negotiating team, "Iran's economic benefit from the deal, observing the country's 'red lines' and preserving (our) indigenous nuclear capability and technology is of serious interest", IRNA reported.
A European official said on Thursday: “It has been agreed that (removing the Guards from the FTO list) will be discussed in the future once the U.S. and Iran can meet directly.”
Tehran also demands that the International Atomic Energy Agency drop its assertions about Iranian nuclear activity, objecting to the U.N. watchdog's report last year that it had failed to fully explain uranium traces at undeclared sites.