Iran has confirmed it has offered new concessions on its controversial nuclear programme in talks with the European Union.
However, the Islamic Republic also warned of a "response" if the Europeans and the UN's atomic watchdog again took a tough line against the Islamic republic.
"If the Europeans do not respect their commitments or present an illogical or harsh resolution, Iran has already decided its response," said top national security official Hassan Rowhani on Wednesday.
Rowhani confirmed Iran was in talks with the EU ahead of a 13 September meeting of the International Atomic Energy Agency (IAEA), with one concession on the table being a renewed suspension on the assembly of centrifuges used to enrich uranium.
Iran is likely to face an ultimatum
at the upcoming talks in Vienna
In high-level talks with the current EU presidenct the Netherlands, Rowhani denied that Iran was seeking nuclear weapons, but said it would not abandon its programme to develop nuclear power for civilian purposes.
On Tuesday, diplomats at the IAEA headquarters in Vienna said Iran was ready again to suspend its efforts to assemble centrifuges in order to avoid being brought before the UN Security Council.
Britain, Germany and France have been negotiating with the aim of getting Iran to "fully suspend any uranium enrichment activities, including making any components for centrifuges", said a Western diplomat in Vienna.
Enriched uranium can be used to provide fuel for reactors working to produce electric energy, as well as nuclear warheads.
Iran recently resumed production of centrifuges, in reaction to a critical resolution adopted by the IAEA board of governors after its last review of the Iran dossier in
"If the Europeans do not respect their commitments or present an illogical or harsh resolution, Iran has already decided its response"
Hassan Rowhani, Iran's top national security official
At the beginning of September, Tehran also announced that it planned to convert 37 tonnes of "yellow cake" uranium into uranium hexafluoride gas, an element necessary for the enrichment of uranium.
Nuclear experts have said that such a large amount could in theory be used to make one or more nuclear warheads.
The United States accuses Iran of covertly trying to develop a nuclear bomb and has sought to have the IAEA refer Tehran to the Security Council for possible sanctions.
Tehran maintains that it is merely trying to meet increasing domestic energy demands and free up its vast oil and gas reserves for export.