Iran's chief nuclear negotiator Saeed Jalili sounded a defiant note ahead of a new round of talks with world powers in Kazakhstan, saying on Thursday they had to recognise Iran's right to a nuclear programme to see any breakthrough.
Jalili also said the Islamic Republic would defend its right to enrich uranium with "more rigour" after its presidential election in June.
"The impact of the election will be that ... our people will defend its right with more rigour," he said in a speech at a university in the Kazakh city of Almaty.
Addressing the round of talks, due to start on Friday and last through Saturday, Jalili added: "We think our talks tomorrow can go forward with one word. That is the acceptance of the rights of Iran, particularly the right to enrichment."
World powers suspect Iran's uranium-enrichment programme has a covert military dimension and are asking Tehran to suspend refining uranium to higher levels.
Tehran denies it is seeking to reach the capability to make bombs and says its atom work is for energy generation and medical research.