UN nuclear watchdog chief Yukiya Amano arrived in Tehran today as world powers pressed efforts to clinch a deal on Iran's nuclear programme following failed negotiations in Geneva.
"I really hope that today we will produce concrete results," said Amano ahead of a meeting with Ali Akbar Salehi, Iran's nuclear chief.
The International Atomic Energy Agency (IAEA), Amano was quoted as saying on English channel Press TV, "is committed to resolve all outstanding issues to ensure Iran' nuclear programme is exclusively for peaceful purposes".
The IAEA conducts regular inspections of Iran's nuclear facilities but it also wants to investigate possible Iranian efforts before 2003, and possibly since, to develop a nuclear weapon.
In particular it wants to visit the Parchin military base southeast of Tehran, where intelligence evidence suggests Iran may have carried out weaponisation research.
Iran denies seeking or ever having sought nuclear weapons, and says the claims are based on faulty intelligence from agencies such as CIA and Israel's Mossad.
Diplomats have insisted they are closing in on an agreement to curb Iran's nuclear programme despite the failure to clinch a long-sought deal in marathon negotiations in Geneva at the weekend.
Hopes for a deal had soared after top diplomats rushed to Geneva to join the talks, but faded again as cracks began to appear among world powers when France raised concerns over a heavy water reactor being built at Arak. The talks ended in the early hours of Sunday.
But diplomats insist they are zeroing in on an agreement to lift some of the crippling sanctions on Iran in return for the freezing of much of its nuclear programme, and plan to meet again from November 20.