However, Gholamreza Aghazadeh - who is also Iran's vice president - reiterated that his country would never give up nuclear fuel production.
"The Islamic Republic will not engage in activities such as gas injection or enrichment during negotiations," Aghazadeh was quoted as saying by the official IRNA news agency on Saturday.
It was not immediately clear whether Aghazadeh was referring to talks on Iran's nuclear activities at the International Atomic Energy Agency (IAEA) or to lower level talks aimed at reviving dialogue with the European Union.
Iran's resumption of uranium conversion earlier this year, the step before enrichment, severed talks with Britain, France and Germany.
In the conversion process, Iran converts uranium ore into uranium hexafluoride gas. Aghazadeh made no mention of stopping this work, which is a goodwill gesture EU countries have sought as a basis for rebuilding dialogue.
Enrichment is the next step, when the gas is pumped into centrifuges to produce enriched uranium.
"The idea of producing uranium hexafluoride in Iran and enriching it elsewhere is a failed idea"
Gholamreza Aghazadeh, Atomic Energy Organization Chief
Iran has not threatened an immediate start to enrichment and many scientists believe Tehran could still be several years from mastering centrifuge technology.
The IAEA board of governors in November decided not to refer Iran to the Security Council for possible sanctions to give more time to a plan that Russia enrich Iran's uranium.
Aghazadeh repeated this compromise would not work. "The Islamic Republic has no doubt it will begin production of nuclear fuel at some stage," he said.
"The idea of producing uranium hexafluoride in Iran and enriching it elsewhere is a failed idea," he added.