A senior United Nations official visited all of Iran's main atomic sites last week, an Iranian news agency reported, as the Islamic Republic looks to restart talks with world powers about its nuclear program.
Herman Nackaerts, the head of the "safeguards" department of the International Atomic Energy Agency (IAEA), spent five days in Iran on a rare visit that coincided with a new push by Russia to re-start diplomatic talks.
The trip also happened as Iran started to move some of its uranium centrifuges to an underground bunker that would be less exposed to any strike by Israel or the United States.
Both countries say military action is a possible last resort to stop Iran getting the bomb. Tehran says its nuclear ambitions are entirely peaceful.
"During this trip, the delegation visited Bushehr nuclear plant, enrichment facilities in Natanz and Fordow, nuclear sites in Isfahan ... and also the Arak heavy water reactor," the semi-official Fars news agency quoted Iran's ambassador to the IAEA, Ali Asghar Soltanieh, as saying.
Nackaerts, whose department is responsible for ensuring that nuclear material is not used for weapons, met Iran's nuclear chief Fereydoun Abbasi-Davani.
"There were talks on how to expand cooperations with the Agency and how to answer some of the Agency's questions," Soltanieh said.
Iran is subject to four rounds of UN sanctions, as well as much tighter U.S. and European Union measures, due to its refusal to halt enriching uranium, a process that produces fuel for power stations but can also make nuclear bombs.
The IAEA was not immediately available to comment
Want to enjoy 'Zen' reading - with no ads and just the article? Subscribe todaySubscribe now