A tweet on Thursday afternoon [April 8]  from Rafael Mariano Grossi, head of the International Atomic Energy Agency (IAEA), featuring a picture of him with Iran’s deputy foreign minister Abbas Araghchi, suggests talks on reviving Iran’s 2015 nuclear deal with world powers may be making progress.

Grossi noted that he and Araghchi, leading the Iranian delegation, had conducted a “thorough exchange” on “current consultations and ongoing bilateral activities” as the IAEA continued “its professional technical verification and monitoring in Iran, in support of [the] JCPOA and other matters.”

Iran's chief negotiator Araghchi tweeted on Thursday, "We're not in a position to say whether JCPOA talks have been positive or not. For sure they've not been negative. I can say that the talks are constructive & moving forward...It's not an easy job."

Current state of play in Vienna is that Britain, China, France, Germany, Iran and Russia, the remaining parties to the nuclear deal – the JCPOA (the Joint Comprehensive Plan of Action) –are due to hear back on Friday from two expert-level groups set up on Tuesday to designate measures to revive deal: which United States sanctions should be lifted, and which of the post-2019 steps in Iran’s nuclear program should be reversed. A US delegation in Vienna led by Rob Malley – while not involved in the formal talks – is in indirect contact from a separate hotel.

Grossi pointed out back in December, even before President Joe Biden took office wanting to return the US to the JCPOA, that reviving the deal required a plan agreed by the politicians for sequencing steps by the US and Iran, and which the IAEA could then monitor.

The role of the expert groups in Vienna is to cut through the complexities and rhetoric. Some steps taken by Iran, especially in research and development, are now perhaps irreversible, while the Trump administration in its final weeks levied sanctions on Iran, ostensibly unrelated to nuclear program, that it said would complicate efforts by a Biden administration to revive the agreement.

Mikhail Ulyanov, Russia’s ambassador to international organizations in Vienna, said Thursday morning that he expected preliminary reports by Thursday evening. "Two expert-level groups continue their work in Vienna on US sanctions lifting and return of Iran to full compliance with its nuclear commitments under JCPOA,” Ulyanov tweeted.

Iran has refused face-to-face talks with the American until the US returns to the JCPOA, which US President Donald Trump left in 2018 before imposing draconian sanctions. Hence the US delegation in Vienna, led by Malley, is reportedly liaising though the French.

Before leaving for Vienna, Malley told PBS news on Saturday that Washington was ready for “that painstaking work of looking at those sanctions and seeing what we have to do so that Iran enjoys the benefits that it was supposed to enjoy under the deal.” Malley said the US would “remove those sanctions…inconsistent with the deal, if Iran is prepared to…reverse the steps..in violation of its nuclear commitments.”

Away from Vienna, Iran and US government spokesman on Wednesday had repeated their respective mantra. In Tehran Saeed Khatibzadeh, for the foreign ministry, said Iran would return to JCPOA nuclear limits once the US removed "all imposed, re-imposed and re-labeled sanctions." In Washington Ned Price, for the State Department, said the US was prepared to lift sanctions inconsistent with the JCPOA, while stressing he could not offer "chapter and verse on what those might be."