Britain, France and the United States are pushing for a new sanctions resolution in the coming week after the UN atomic watchdog said it could still not confirm if the Iranian atomic drive was peaceful.

"Some Western countries want to follow the wrong path and we suggest they take heed from their past experiences," Javad Vaeedi, a top national security official, was quoted as saying by the state-run IRNA news agency.

"Choosing the wrong path and adopting a new resolution will have a cost for those countries," he added.

President Mahmoud Ahmadinejad on Saturday warned of "firm reprisals" against any country leading the way to impose new sanctions, adding that Iran was "not joking."

"They could spend 100 years passing resolutions but it will not change anything," he said in an interview with state television.

Officials however gave no details over what the reprisals might entail. "We will announce our decision at the right time based on the content of the resolution," foreign ministry spokesman Mohammad Ali Hosseini said.

The International Atomic Energy Agency (IAEA) said on Friday in its latest report that it had made "quite good progress" in its four year-probe into the Iranian nuclear drive.

But crucially for future sanctions, the report said it was still not in a position to determine the "full nature of Iran's nuclear programme" and confirmed Tehran was continuing to defy UN demands by enriching uranium.

The report met with starkly different responses from Western capitals and Tehran.

Iranian officials said the report proved that the nuclear case was now closed, with Ahmadinejad hailing the "historic victory of Iran in its greatest confrontation with the oppressive powers since the Islamic revolution".

But US Secretary of State Condoleezza Rice said the report provided "a very strong case" for moving forward with a third UN Security Council sanctions resolution to punish Tehran's failure to suspend enrichment.

The head of Iran's Atomic Energy Organisation, Gholam Reza Aghazadeh said on Sunday "a resolution is likely to be adopted" against Iran.

"There will be more political pressure and increased propaganda," he told state television. "But there is a price to pay if we want to reach a high position and our country has accepted that."

Tehran has defied calls in previous resolutions for it to freeze uranium enrichment operations, a sensitive process world powers fear could be used to make nuclear weapons.

Iran, OPEC's number two oil exporter, insists its nuclear programme is peaceful and only aimed at generating atomic energy for a growing population whose immense oil and gas reserves will run out in decades.

Meanwhile, top Iranian cleric Akbar Hashemi Rafsanjani accused the United States of unbalancing IAEA chief Mohamed ElBaradei's "mental state" by submitting secret documents just days before the report.

"The US has submitted a stack of documents to disrupt ElBaradei's mental state and has been successful to some extent," said the head of the elite clerical body the Assembly of Experts, according to the state news agency IRNA.

Washington was to host a new round of talks between world powers on Monday ahead of a Security Council meeting on Wednesday and a vote on the resolution text on Friday, US officials said.

The draft text has been brought forward by Britain and France and it remains to be seen how veto-wielding members China and Russia will respond. Four non-permanent members are also said to harbour reservations.

The draft would impose a travel ban on officials involved in Tehran's nuclear and missile programmes and inspections of shipments to and from Iran if there are suspicions they may contain prohibited goods.

But Hosseini brushed off the prospect of further sanctions, saying that they could only cause "slight problems" for the Islamic republic.