The UN's atomic watchdog has confirmed a long-awaited visit to Iran on Sunday, as it seeks answers from Tehran on its nuclear activity.
But analysts say it is likely to end in only vague commitments from Iranian officials.
The International Atomic Energy Agency confirmed the trip a day after Iran's nuclear chief Mohammed Eslami said he hoped the visit would "resolve issues" with the watchdog, which is calling on Tehran to explain the presence of enriched uranium at three undeclared sites.
IAEA director general Rafael Grossi, who has said he hopes the visit will end the impasse with Tehran, is not expected to take part.
The UN watchdog has issued repeated resolutions urging Tehran to co-operate as the prospects of salvaging the 2015 nuclear accord between Iran and world powers grow dimmer.
Despite Iran's claims it wants to resolve problems with the watchdog, allowing a visit from the IAEA does not spell a significant change from its usual tactics, analysts have told The National.
Iran has a pattern of "floating" offers of engaging with the IAEA with "little substantive results", said Naysan Rafati, senior Iran analyst at Crisis Group International.
"While in principle Sunday's visit gives an opportunity for Tehran to seriously address the IAEA's questions on activities at undeclared sites, in practice it may well turn out to be another exchange with vague commitments and uncertain follow-through," he said.
The IAEA had planned to visit Iran last month but the trip was abandoned over Iran's continued failure to provide clear-cut answers.
The agency's 35-member board pressed Tehran for a response in mid-November, with the US saying the time for "empty promises" was over.
"For the US and Europeans this is a clear-cut case of the Islamic Republic failing to meet its obligations," said Mr Rafati.
Sahil Shah, senior Iran policy adviser to the European Leadership Network, said: "The agency has made clear that the explanations Iran has provided to date do not add up, and it is the organisation's job to get to the bottom of where the material that left the traces has ended up."
Iran's hosting of IAEA officials on Sunday may be little more than an attempt to distract its population, an Iran expert told The National last week, as Tehran is executing anti-government protesters who have been rallied against the government for the past three months.
Tehran has given “ample reason” to doubt it is serious about main obstacles to reviving the nuclear deal, said Henry Rome, a senior fellow at the Washington Institute for Near East Policy.
The regime has repeatedly demanded that the IAEA drop its investigations and has made it a core condition for returning to the nuclear accord.
But the international community must resist putting political pressure "to sway one way or the other", said Mr Shah.
"The agency cannot be bullied by Iran or anyone else to simply close the case," he added.
The 2015 nuclear deal lifted sanctions on Iran in exchange for a series of commitments to curb its nuclear programme. It fell apart when former US president Donald Trump withdrew from the accord in 2018, reimposing sanctions on Tehran.
The agreement capped Iran's uranium enrichment at 3.67 per cent, but Tehran has stepped up levels of enrichment and its stockpile of enriched uranium well past the limits of the accord since 2018, and has announced plans to install advanced centrifuges at several nuclear plants.
Failure to revive the deal will not mean the rest of the world is "flying blind", however.
The 1964 Safeguard Agreement allows the IAEA access to most information on Iran's nuclear activity and gives a "good picture" of its increasing stockpiles, said Mr Shah.
However, it does not mean the international community is out of the woods.
Mr Shah said: "Iran is advancing its nuclear activities at a rate where it could eventually be able to produce multiple significant quantities between IAEA inspections, which would make detection and disruption much more challenging."