Iran’s chief nuclear negotiator Saeed Jalili sounded a defiant note ahead of a new round of talks with world powers in Kazakhstan, saying yesterday they had to recognise Iran’s right to enrich uranium to see any breakthrough.

The six powers – United States, Russia, China, France, Britain and Germany – are meeting Iranian negotiators today and tomorrow in the Kazakh city of Almaty, hoping Tehran agrees to scale back its most sensitive atomic work that they suspect is aimed at achieving a nuclear weapons capability.

Iran has refused to do so during a decade of on-and-off negotiations, despite hardening economic sanctions, arguing its uranium enrichment has peaceful purposes only and therefore can continue under international law.

Jalili, speaking at a university in Almaty, said that stance would not change.

“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,” he said.

World powers argue Iran has given up its right to enrich uranium under international rules because it has hidden nuclear work from United Nations inspectors in the past and has refused to open fully to their investigations.

Jalili said Iran would continue to defend its policy regardless of a June presidential election, which Western diplomats say complicates Tehran’s approach to talks.

“The impact of the election will be that ... our people will defend their right with more rigour,” Jalili said.

There is broad unity within the Iranian political establishment on pursuing the nuclear programme and policy on the issue is closely overseen by Ayatollah Ali Khamenei, Iran’s supreme leader who has the last word on all momentous matters.