United Nations nuclear chief Yukiya Amano started talks with senior Iranian officials on Monday, Iranian media reported, on his one-day visit to Tehran that diplomats say could lead to an agreement for further inspections of Iranian nuclear sites.
Hours after his pre-dawn arrival in Tehran, Amano met the head of Iran's nuclear energy organization, Fereydoun Abbasi-Davani, ISNA news agency reported.
The International Atomic Energy Agency (IAEA) chief is also scheduled to meet Iran's chief nuclear negotiator Saeed Jalili and Iranian foreign minister, Ali Akbar Salehi during the day.
Amano voiced optimism upon his arrival in Tehran, saying he was hopeful he would be able to reach a deal to investigate suspected atom bomb research - a possible breakthrough that Iran hopes could help ease Western sanctions pressure and deflect threats of war.
"I really think this is the right time to reach agreement. Nothing is certain but I stay positive," Amano said at Vienna airport, adding "good progress" had already been made.
But though Amano scheduled Monday's talks with Iran at such short notice that diplomats said agreement on new inspections seemed near, few see Tehran convincing Western governments to ease back swiftly on punitive measures when its negotiators meet big power officials in Baghdad on Wednesday.
By promising cooperation with UN inspectors, diplomats say Iran might aim for leverage ahead of the broader negotiations, where the United States and its allies want Iran to halt works they say are cover for developing nuclear weapons. Western sanctions on Iran's energy exports, and threats by Israel and Washington of military action, have pushed up world oil prices.
Western diplomats say Amano, a veteran Japanese diplomat, would only make a rare visit to Tehran if he believed a framework agreement to give his inspectors freer hands in their investigation was close.
"We regard the visit... as a gesture of goodwill," Iranian Foreign Minister Ali Akbar Salehi was quoted as saying by the Iranian student news agency. He hoped for agreement on a "new modality" to work with the UN agency that would "help clear up the ambiguities."
The nuclear watchdog wants access to sites, officials and documents to shed light on activities in Iran that could be used to develop the capability to make nuclear weapons, especially the Parchin military complex southeast of Tehran.
Two meetings between Iran and senior Amano aides in Tehran in January and February failed to make any notable progress. But both sides were more upbeat after a new round of talks in Vienna last week, raising hopes they were making headway.
"We need to keep up the momentum. There has been good progress during the recent round of discussions between Iran and the IAEA," Amano said, adding he did not expect to visit Parchin during his short stay in Tehran. Israel remains skeptical over of IAEA-brokered deal
Israel, convinced a nuclear-armed Iran would pose a mortal threat, has - like the United States - not ruled out air strikes to stop Iran's atomic progress if it deems diplomacy has failed.
Russia's deputy foreign minister said on Sunday that military action against Iran over its nuclear program was being considered in some Western countries.
"It is one of many various signals coming from various sources that the military option is considered as realistic and possible," Sergei Ryabkov told reporters on his way back from the weekend's G8 summit.
Israel has made clear its skepticism about the prospects for diplomacy, saying Iran is just trying to buy time.
"We don't see any readiness from the Iranian side to give up their nuclear ambitions and for them all the engagement, from our point of view, it's clear deception," Foreign Minister Avigdor Liberman said on Sunday.