Save for later Print Download Share LinkedIn Twitter A last-minute concession by Iran that grants the UN nuclear agency greater insight into its nuclear program has raised hopes of a return to the stalled talks in Vienna aimed at reviving the 2015 Iran nuclear deal and easing US sanctions.However, Western officials are warning that further delays -- which give Iran more time to develop its enrichment activities -- make a return to compliance with the nuclear deal harder.Tehran’s reported plans to replace its chief negotiator in Vienna with a hard-liner also risk further complicating the talks.Iran agreed on Sunday to allow the International Atomic Energy Agency (IAEA) to service surveillance cameras at sensitive nuclear facilities and store their data under joint IAEA and Iranian seals.This resolves what the head of the agency, Rafael Grossi, described as "the most urgent issue" after he visited Tehran over the weekend.Data collection and storage is seen as a vital interim measure while efforts continue to resurrect the so-called Joint Comprehensive Plan of Action (JCPOA).The US unilaterally withdrew from the agreement in 2018 and Iran then stopped complying with its terms too.Iran also pledged its future cooperation on unspecified "issues of mutual interest" over the weekend, which analysts suggest was a reference to Iran's obstruction of the investigation into undeclared nuclear materials.Positive StepGrossi told reporters on his return to Vienna, where the IAEA is based, that the understanding reached with Tehran was "not a permanent solution" but "a stopgap."Enrique Mora, the EU official coordinating the talks, called the compromise a positive step that created "space for diplomacy." He tweeted that the "EU’s aim remains full #JCPOA implementation by all."Sunday’s agreement, which followed Tehran's last-minute decision to authorize Grossi's visit, came after Russia put significant pressure on Iran. It also came just a day before the start of a quarterly IAEA board meeting.The agreement appears to have defused the threat of a Western-backed resolution criticizing Iran for hampering the agency's work. Such a resolution could have dealt a hammer blow to the chances of fresh talks in Vienna succeeding.The IAEA released its latest quarterly report on Iranian compliance with the 2015 nuclear deal last week.The report documented Iran's failure to respond to the IAEA's requests for access to its monitoring equipment and said this was "seriously compromising" the agency’s "continuity of knowledge." It also provided details of Iran's estimated stockpiles of enriched uranium and the advanced centrifuges that it has deployed.Hanging by a ThreadIt's unclear when the Vienna talks could resume, and what kind of position Iran would adopt. The country's new hard-line President Ebrahim Raisi appears determined to show that Iran will not be pressured into negotiating.Iran's Foreign Minister Hossein Amir-Abdollahian told his British counterpart Dominic Raab in a phone call on Monday that the new Iranian government was holding "internal consultations" about how to continue the negotiations, the state-run IRNA news agency reported.Henry Rome, an Iran expert at the Eurasia Group think tank, described the rumored replacement of Chief Negotiator Abbas Araghchi as a step that would be "very negative" for the talks."While Tehran averted a worst-case scenario for the deal, its minimal compromises and continued reluctance to return to talks mean the agreement continues to hang by a thread," he said in a note.Ali Bagheri-Kani, a hard-liner like Amir-Abdollahian, was emerging on Monday as a possible deputy foreign minister and replacement to Araghchi.And although the country's supreme leader -- to whom Bagheri-Kani is related -- ultimately determines nuclear policy , experts say the negotiating team still matters. Meanwhile, Iran's advances in uranium enrichment are clearly worsening the chances of a JCPOA revival.Echoing earlier comments by US Secretary State of State Antony Blinken, his spokesman noted on Thursday that a mutual return to compliance was "still within the realm of possibility."However, the spokesman also warned that the benefits of the JCPOA in preventing Iran from obtaining a nuclear weapon "continue to be eroded the longer this goes on."