A senior Iranian cleric has set out four new conditions for allowing the United Nations to make snap inspections of the country's nuclear facilities.
Tehran says its nuclear programme is for energy
Former President Akbar Hashemi Rafsanjani said they included from protecting Iranian security to continuing civilian nuclear projects.
Mr Rafssanjani said his country had the right to the same inspection conditions as those demanded by the United States.
Officials from the UN's nuclear watchdog are in Tehran to persuade Iran to accept tougher inspections.
The UN has given Iran until 31 October to convince it that it is not seeking to produce nuclear weapons.
Mr Rafsanjani, a leading cleric in the Islamic state, referred to the new conditions in a sermon at Friday prayers at Tehran University which was broadcast live on television.
The four conditions set out were:
- That Iranian national security is not jeopardised
- That Islamic values and holy sites are not affected
- That military secrets unconnected with the nuclear programme are not disclosed
- That other states "fulfil" their duty to assist Iran with its civilian nuclear programme
"Our conditions... are the same as those the Americans want," Mr Rafsanjani said.
The US has signed, but not ratified, an international agreement permitting snap inspections of nuclear sites - the Additional Protocol to the nuclear Non-Proliferation Treaty (NPT).
Mr Rafsanjani said that pressure on Iran to prove it had no nuclear weapons ambitions was a "scandal".
"The hypocritical policy of the Americans and Westerners has
no justification," he said.
It is unclear of the new conditions have the official backing of the Iranian leadership which has been negotiating with a team from the UN's International Atomic Energy
Agency (IAEA) since Thursday.
If Iran fails to convince the IAEA by the end of October that it is not seeking to produce nuclear weapons, the issue could be referred to the UN Security Council, and Iran could face sanctions for breaching the NPT.
The BBC's Jim Muir reports that the 31 October deadline has stirred anger in Iran, which has been giving out mixed signals about how far it will co-operate.
The IAEA has already given Iran a detailed programme and timetable for the work it wants its inspectors to do during the four remaining weeks.
The question is whether Iran will go along with that programme and answer the many questions the agency is also asking, such as how traces of highly-enriched weapons-grade uranium came to be found at two Iranian facilities.
Iran's ambassador to the IAEA, Ali-Akbar Salehi, told the BBC that Iran would answer such questions - handing over, for example, lists of the imported components on which it says the contamination was brought in from outside the country.
Mr Salehi said Iran would also co-operate in allowing further inspections and the taking of more samples.
But Iranian officials have made it clear that it is not going to be a one-way street.
North Korean way?
They want practical recognition of Iran's right to produce peaceful nuclear energy and to process their own uranium for fuel - something the IAEA has asked them to stop doing, at least for the time being.
Iran also wants assurances that if it signs an additional protocol that would allow tougher inspections, there would be limits to how intrusive they would be - and also that signing that protocol would not spur the Americans to make more demands.
This has emerged as a substantial middle ground here, after several weeks of widely-divergent views and arguments behind the scenes.
Some hardliners have been arguing that Iran should scrap its NPT commitments altogether and go the way of North Korea.
That is certainly not the official position, though it cannot be ruled out if the talks go badly wrong.
One problem, our correspondent says, could be that the Iranians want to negotiate on many points, while the IAEA officials are bound by the resolution passed by the agency's board of governors last month and have little room for manoeuvre.