Interfax cited an unidentified Iranian delegation member as saying Iran might also hold one-on-one talks with Russia, but ruled out direct negotiations with the United States in Almaty.
Officials from both sides have set low expectations for a breakthrough in Almaty — the first time the high-level negotiators have met since last June's meeting in Moscow that threatened to derail the delicate efforts.
While Mann acknowledged the Almaty talks would unlikely lead to a firm outcome, he insisted that it remained an important stepping stone toward a definitive solution.
"We're not interested in talks just for talk's sake. We're not here to talk, we're here to make concrete progress," Mann said.
The first session of talks were held in private at a hotel in Almaty and were deemed so sensitive that reporters were not allowed on the premises Tuesday save for a handful of TV cameras and photographers allowed to watch Ashton greet Saeed Jalili, secretary of Iran's Supreme National Security Council.
Tehran maintains it is enriching uranium only to make reactor fuel and medical isotopes, and insists it has a right to do so under international law. It has signaled it does not intend to stop, and U.N. nuclear inspectors last week confirmed Iran has begun a major upgrade of its program at the country's main uranium enrichment site.
Over the last eight months, the international community has imposed heavy economic sanctions on Iran, hoping they would be so painful that the Islamic republic's clerical regime would slow its nuclear program out of a moral obligation to its public. Negotiators now hope that easing some sanctions will make Tehran more agreeable to halting production of 20 percent enriched uranium — the highest grade of enrichment that Iran has acknowledged and one that experts say could be turned into warhead grade in a matter of months.
World powers also want Iran to suspend enrichment in its underground Fordo nuclear facility, and to ship its stockpile of high-grade uranium out of the country.
Mohammadi said shuttering Fordo was "out of the question" and that Iran first wants the U.N. Security Council to withdraw all of the sanctions it has heaped on the nation.
Iran has been unimpressed with earlier offers by the powers to provide it with medical isotopes and lift sanctions on spare parts for civilian airliners, and new bargaining chips that Tehran sees as minor are likely to be snubbed as well.
Iran insists, as a starting point, that world powers must recognize the republic's right to enrich uranium.
Associated Press writers Charles Hutzler in Beijing, Tia Goldenberg in Jerusalem, George Jahn in Vienna and Matt Lee in Berlin contributed to this report.
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