The head of the UN nuclear watchdog, Yukiya Amano, is to travel to Iran to have meetings about a deal to rein in the Iranian atomic programme, diplomatic sources told AFP.
Amano, who has been closely involved in this week's negotiations between global powers and Iran in Vienna, would leave Wednesday for meetings in Tehran on Thursday, the sources close to the talks said, asking not to be identified.
Iranian media said Amano, the director general of the International Atomic Energy Agency (IAEA), has been invited to Tehran to discuss "past activities" and how to resolve differences over Iran's disputed nuclear programme.
He would meet with Iranian President Hassan Rouhani and the chairman of Iran's Supreme National Security Council, Ali Shamkhani, the official IRNA news agency reported on Wednesday.
"The goal of Yukiya Amano's trip is to talk about past activities and receive Iran's suggestions on how to resolve the differences," IRNA quoted a source close to the Iranian negotiating team as saying.
Amano met Monday with US Secretary of State John Kerry. And on Wednesday he was seen slipping into the elegant Coburg Palace in Vienna where teams of negotiators have been working virtually around the clock to seal a deal.
Under the mooted deal, it will be up to the IAEA, which already keeps close tabs on Iran's declared nuclear sites with between four and 10 inspectors on the ground on any given day, to verify that Iran really does reduce its capacities.
But the so-called P5+1 powers -- Britain, China, France, Germany, Russia and the United States -- also want the IAEA to have wider inspection rights to verify any suspicious activity that might indicate work in secret on a nuclear bomb.
This could include the IAEA visiting military bases, something that Iranian supreme leader Ayatollah Ali Khamenei last week rejected as a "red line".
ISNA news agency reported that Amano's visit came at the request of Iran.
"When Iran did not accept the (agency to) interview nuclear scientists, the agency sought Iran's suggested solutions and Iran will offer its solution in this trip," it said.
Amano's trip is also expected to help resolve long-standing suspicions about the possible military dimensions of Iran's nuclear programme, ISNA added.
A top Iranian diplomat told the agency the issue could be resolved through an agreed "roadmap of cooperation."