The meetings between the EU's envoy, Enrique Mora, and top Iranian officials come at a sensitive moment for talks to revive the deal, as the glimmers of a resolution to some of the thorniest issues in the negotiations have emerged.
The report on the talks in Tehran gave scant detail, saying only that the diplomats discussed the latest on the nuclear agreement, with Iran's top nuclear negotiator Ali Bagheri Kani repeating that Iran believed a deal was within reach if America was ``realistic'' in its demands.
Former President Donald Trump abandoned the nuclear deal in 2018 and re-imposed crushing sanctions. Iran gradually breached the agreement with a massive expansion of its nuclear work.
Nuclear talks broke off earlier this month as last-minute wrangles in Vienna coincided with Russia's invasion of Ukraine and financial sanctions imposed by the West on Moscow.
But officials have since made encouraging noises. Russia appeared to back down from its earlier demand that its trade with Iran be exempted from Western sanctions.
And for the first time, Iran's top diplomat on Saturday publicly signaled flexibility over Tehran's demand that Washington stop designating the country's Islamic Revolutionary Guard, its powerful paramilitary force, as a foreign terrorist organization.
The prospect of the designation's removal had alarmed America's Mideast allies, such as Israel, which fiercely opposed the original nuclear deal and argued that easing sanctions on the Revolutionary Guard would embolden Iranian-backed militant groups from Hezbollah in Lebanon to the Houthis in Yemen.
In a visible sign that shared regional anxiety over a renewed nuclear deal was growing, the Israeli government hastily arranged an unprecedented summit of top diplomats from Arab countries that have normalized ties with Israel along with U.S. Secretary of State Antony Blinken.
``We are both committed, both determined that Iran will never acquire a nuclear weapon,`` Blinken said alongside Israel's foreign minister, seeking to reassure his jittery counterparts before the gathering.
Remarks on Sunday by the U.S. special envoy for Iran, Robert Malley, underscored the U.S. limitations that have frustrated allies. He declined to discuss details of the nuclear negotiations, but reiterated that America had failed to secure a broader deal with Iran that would restrict its ballistic missiles program and curb its regional military policies.
``It would have been better, but (the nuclear deal) was not intended to, it wasn't able to address the other issues,'' Malley told the Doha Forum, a Middle East policy conference in Qatar. ``Many in the region view the IRGC in the same way we do. ... But we know this is not a deal that's going to address that.``
However, Malley was quick to stress that no matter what happens to the Guard's terrorism designation, separate sanctions over its ballistic missile development and alleged human rights violations would remain.
Anxieties over a restored deal also were on stark display in Tehran, laying bare deep fissures in Iran's divided political system.
Hard-liners opposing any hint of rapprochement with the West appeared to fret about possible Iranian compromises after Foreign Minister Hossein Amirabdollahian told state TV that the Revolutionary Guard had accepted that the terrorist designation would stay in place so that Iran could pursue ``whatever is necessary for the interests of the country.''
Hossein Shariatmadari, appointed by Supreme Leader Ayatollah Ali Khamenei as editor-in-chief of hard-line Kayhan daily, rebuked Amirabdollahian's remarks as ``unexpected and strange.''
In an interview late Saturday with the semiofficial Fars news agency, Shariatmadari insisted that the foreign minister had misunderstood the Revolutionary Guard when he spoke on the force's behalf.
``Attributing this statement to Guard commanders does not correspond to any of the well-known characteristics of Guard commanders,'' he said, adding that Amirabdollahian had falsely given the impression of the Guard's ``surrender.''
From the Doha Forum, Sayyid Kamal Kharrazi, a foreign policy advisor to Iran's supreme leader, also struck a tough line, rejecting the United States' continued sanctions on the Revolutionary Guard.
``A national army cannot be listed as a terrorist group,'' Kharrazi told the audience. ``That is very important for Iranians to have the IRGC removed from the list. ... They are not going to compromise on that.``
In an Instagram post, Amirabdollahian expressed regret that his comments had been ``misinterpreted'' and tried to assuage domestic unease by promising he had not backed down from any Iranian ``red lines.''
Still, ambiguity prevailed as Malley and Kharrazi offered starkly different assessments from Doha about the chances of the deal's looming revival.
``It's imminent,'' said Kharrazi.
Malley appeared more skeptical.
``I can't be confident it's imminent,'' he said. ``It's not just around the corner and it's not inevitable.''