ANKARA - Iran's Supreme Leader, Ayatollah Ali Khamenei, said on Wednesday Tehran would not accept "unreasonable demands" by world powers over its disputed nuclear programme and ruled out letting inspectors interview its atomic scientists.
The comments, broadcast live on state TV, were the latest in a series of forthright statements on inspections in the countdown to a June 30 deadline to resolve a decade-old standoff over Iran's nuclear work. Responding to Khamenei, the United States made clear that failure to resolve questions about Iran's past nuclear work would be a problem in the negotiations.
"We will never yield to pressure ... We will not accept unreasonable demands ... Iran will not give access to its (nuclear) scientists," Khamenei said.
"We will not allow the privacy of our nuclear scientists or any other important issue to be violated."
Khamenei, who has the final say for Iran on any deal, last month ruled out any "extraordinary supervision measures" over nuclear activities and said military sites could not be inspected.
The UN International Atomic Energy Agency (IAEA) has been trying to investigate Western allegations that Iran has worked on designing a nuclear warhead. Iran says its nuclear programme is peaceful and that it is working with the IAEA to clear up any suspicions.
UN inspectors regularly monitor Iran's declared nuclear facilities, but the IAEA has complained for years of a lack of access to sites, equipment, documents and people relevant to its probe.
Western officials say Iran must step up co-operation with the IAEA if it wants to reach a broader diplomatic deal with world powers that would gradually end crippling financial and other sanctions on the oil producer.
"They say we should let them interview our nuclear scientists. This means interrogation," Khamenei said.
"I will not let foreigners talk to our scientists and to interrogate our dear children ... who brought us this extensive (nuclear) knowledge."
Iran has yet to answer questions about two areas of the investigation into alleged research activities that could be applicable to any attempt to make nuclear bombs - explosives testing and neutron calculations.
Iran reached a tentative deal with the powers on April 2 to allow UN inspectors to carry out more intrusive, short-notice inspections under an "Additional Protocol" to the Non-Proliferation Treaty. But there have been sharply differing interpretations from both sides on the details of that access.
"If we don't get the assurances we need on the access to possible military dimension-related sites or activities, that's going to be a problem for us," US State Department spokeswoman Marie Harf told reporters in Washington.
"We and Iran have agreed that we will undertake a process to address possible military dimensions (of past nuclear work), and part of that includes access," she said. "Under the Additional Protocol, ... which Iran will implement and has said they will implement as part of this deal, the IAEA does get access."
When asked whether there had been some progress since April, French Foreign Minister Laurent Fabius, who has been perceived as the most demanding in the talks, said the negotiations now had to discuss the deal's annexes, which was not the case yet.
He said Iran also had to offer real transparency in its military activities as part of the deal, including rapid access to IAEA inspectors to all sites.
"What happens if Iran doesn't comply. How much time will we have to check? In the current text, it's 24 days, but in 24 days a lot of things can disappear," Fabius said.
Negotiators from Iran and the powers met in Vienna on Wednesday to try to iron out remaining differences, including the timing of sanctions relief and the future of Iran's atomic research and development programme.
"There has to be concrete commitments on the enrichment activities allowed for length of the accord, including a phased reduction in the number of centrifuges at the underground site of Fordow and an efficient mechanism to restore sanctions if Iran does not respect its commitments," Fabius said.
Talks between EU political director Helga Schmid and Iranian negotiators Abbas Araqchi and Majid Takht-Ravanchi will run until Friday, with technical experts meeting in parallel, the EU said in a statement.