Top Iranian nuclear negotiator Hossein Mousavian has ruled out a long-term suspension of uranium enrichment.
Mousavian: Referral to the UN Security Council is an empty threat
Mr Mousavian told the BBC it was completely illogical for the international community to ask Iran to stop its enrichment activities.
What was being considered was a suspension for a few months, he said.
On Wednesday, Iran's spiritual leader, Ayatollah Ali Khamenei, said illogical demands from the Europeans would lead Iran to break off talks.
In an interview with the BBC, Mr Mousavian, the Secretary of the Foreign Policy Committee of the Supreme Council for National Security, said the key question was whether Europe is asking Iran to suspend enrichment of uranium or stop it altogether.
He said an indefinite suspension for a decade was not going to work.
Iran had in mind a suspension for two or three or four months and would not consider a very long time frame.
Mr Mousavian said asking Iran to stop enrichment altogether was illogical.
What Iran is offering the Europeans instead is a series of objective guarantees and confidence building measures to prove it is not diverting uranium for a weapons programme.
But it is not at all clear that will be enough and if no deal is reached, Europe is threatening immediate referral of Iran to the United Nations Security Council.
But Mr Mousavian described referral as an empty threat because he said the Security Council could not do anything serious against Iran - like an oil embargo - because it would double world oil prices.
And he said Iran had been preparing for referral to the Security Council since June when it began to lose hope in the dialogue with Europe.