The UN nuclear watchdog will try to persuade Iran to address questions about its suspected nuclear weapons research at a meeting on Friday, more than two months after previous talks ended in failure.
The International Atomic Energy Agency (IAEA) issued a brief statement confirming the talks, to be held at Iran's diplomatic mission in Vienna, after diplomats told Reuters earlier on Tuesday that they expected a new meeting on that day.
The talks, to be attended by senior IAEA officials, will take place just a few days before the UN agency is due to issue its latest quarterly report on Iran's disputed nuclear program.
They could give Iran a last minute chance to influence the content of the report if it were to offer concessions to UN inspectors seeking access to sites, officials and documents they say they need to conduct their long-stalled inquiry.
However, Western diplomats said they did not expect any breakthrough.
Iran denies Western allegations it is seeking to develop nuclear weapons technology. But its refusal to curb and be more transparent about its nuclear activity has led to increasingly tough sanctions and sparked speculation that Israel, Tehran's arch foe, might attack Iranian nuclear sites.
Iran "will try something", one of the diplomats said. But, "I don't see any bridging of the differences on the issues that were outstanding" in the last meeting on June 8.
The IAEA said its delegation would be led by Herman Nackaerts, its chief inspector, and Rafael Grossi, assistant director general for policy.
The IAEA report - which is expected to say Tehran is pressing ahead with its uranium enrichment program - will be submitted to the agency's 35-nation governing board, which meets on September 10-14 with Iran likely to again dominate the agenda.
West suspects Parchin clean-up
The IAEA has failed in a series of high-profile meetings with Iran since January to make it end its stonewalling of the agency's inquiry.
Analysts say Iran seems to be using its talks with the IAEA to gain leverage in separate talks with six world powers that have made little headway since they resumed in April after a 15-month gap.
The six powers - the United States, France, Russia, Germany, Britain and China - also want Iran's full cooperation with the UN watchdog. But their more immediate demand is that Iran stop activity that could give it the capability to produce nuclear weapons.
Iran is seeking recognition of what it says is its legal right to enrich uranium - which can yield either fuel for nuclear power stations or for bombs - and a lifting of harsh economic sanctions on its economically vital oil exports.
The UN watchdog has been pressing Tehran for an agreement that would give it immediate access to the Parchin military complex, where it believes explosives tests relevant to the development of nuclear arms have taken place.
Western diplomats suspect Iran has been purging the site of incriminating evidence, a charge Tehran has dismissed.
Iran says there must first be a wider accord with the IAEA on how the agency's investigation should be conducted before it allows inspectors into Parchin.
"We don't have any expectation that it will be a substantive meeting," one of the diplomats said about Friday's talks.
Nuclear expert Mark Hibbs of the Carnegie Endowment for International Peace said Iran in the June meeting had added "more unacceptable conditions" to the terms of a proposed framework deal for the IAEA's investigation.
"They would have to do a serious climb down for the IAEA to conclude a new agreement," Hibbs told Reuters.