VIENNA - The UN nuclear watchdog will press Iran on Friday for a deal that would enable its inspectors to visit a military complex where they suspect atom bomb research has taken place, but Western diplomats are skeptical a breakthrough will be reached.
World powers will be watching the IAEA-Iran meeting in Vienna closely to judge whether the Islamic Republic is ready to make concessions before its broader talks with them later this month in Moscow on their decade-old nuclear dispute.
Both Iran and the International Atomic Energy Agency, the UN nuclear body, say significant progress has been made on a framework agreement to resume a long-stalled IAEA investigation into Tehran's atomic activities.
But differences remain on how the IAEA should conduct its probe, and the United States said this week it doubted whether Iran would give the UN agency the kind of access to sites, documents and officials it needs.
"I'm not optimistic," Robert Wood, the acting US envoy to the IAEA, told reporters on the sidelines of a meeting of the UN agency's governing board. "I certainly hope that an agreement will be reached but I'm not certain Iran is ready."
His skepticism was reinforced by defiant remarks by Tehran's envoy to the IAEA, who accused the UN body on Wednesday of acting like a Western-manipulated spy service and said that Iran's military activities were none of its business.
Ambassador Ali Asghar Soltanieh said Iran would work with the IAEA to prove that Western allegations that Iran wanted a nuclear weapons capability were "forged and fabricated". Iran says its nuclear program is aimed at generating electricity.
But he also said Iran would "not permit our national security to be jeopardized," suggesting it might limit the scope of the UN inspectors' investigation.
A European diplomat said Soltanieh's remarks signaled that Iran would be in no mood to compromise in Friday's Vienna talks.
Western officials, who suspect Iran is dragging out the two sets of talks to buy time for its nuclear program, say the value of any deal will depend on how it is implemented.
The IAEA wants Iran to address concerns over intelligence information pointing to research and tests in Iran - some of which may still be in progress - relevant for developing a nuclear weapons capability.
Iran may give IAEA increased access ahead of P5 + 1 talks
The European Union stressed that the IAEA should be free to conduct its probe in an open way and not be forced to close areas of inquiry prematurely, suggesting this may still be a bone of contention.
"The Agency must be able to revisit areas as their work progresses and as new information becomes available," the 27-nation EU said in a statement to the IAEA's 35-nation board.
The IAEA's immediate priority is gaining access to the Parchin military complex southeast of Tehran, where it believes Iran built a steel vessel in 2000 for high explosives tests and may now be cleaning the site of any incriminating evidence.
Iran says Parchin is a conventional military facility and has dismissed such allegations as "ridiculous."
Diplomats and analysts say Iran may offer the IAEA increased cooperation as a bargaining chip in its negotiations with world powers, which resumed in April after a 15-month hiatus and are to continue in the Russian capital on June 18-19.
Those talks are aimed at defusing tension over Iran's nuclear program that has led to increasingly tough Western sanctions on Iran, including an EU oil embargo from July 1, and created fears of a war in the region.
If Iran does not agree to give the IAEA immediate access to Parchin before the Moscow talks, it would be a sign that Tehran "continues to believe it is in a relative position of strength," said Bruno Tertrais of the Strategic Research Foundation.
Full transparency and cooperation with the IAEA is one of the elements the world powers - the United States, Russia, France, Britain, China and Germany - are seeking from Iran.
But they also want Iran to halt its higher-grade uranium enrichment, which Tehran says it needs for a research reactor but which also takes it closer to potential bomb material.
For its part, Iran wants sanctions relief and international recognition of what it says is its right to refine uranium.
"Parchin access is not among the key concessions that the six powers are seeking from Iran in Moscow," said nuclear proliferation expert Mark Fitzpatrick of the International Institute for Strategic Studies, a think-tank in London.
"They are focused on confidence building measures that would limit Iran's ability to make a sprint for a nuclear weapon."