Negotiating the level and amount of uranium enrichment going forward is fine, but giving up even some of the enriched uranium Iran has already stockpiled is out of the question, Deputy Foreign Minister Abbas Araqchi said ahead of six-party talks in Geneva, Switzerland, aimed at finding a diplomatic solution to Iran's contentious nuclear program.
"Shipping out the [enriched] material is a red line for Iran," Araqchi told Iranian state TV.
Western officials also want Iran to stop enriching uranium up to 20 percent purity, which international powers consider dangerously close to weapons-grade quality, and close its deep-underground enrichment bunker in Fordo, south of Tehran, near the holy city of Qom.
The Fordo plant -- which Washington and Jerusalem allege is part of a covert Iranian weapons program -- is Iran's most heavily armed and protected nuclear site, controlled by the country's elite Islamic Revolutionary Guard Corps.
Araqchi is expected to lead the Iranian delegation in Geneva that will meet with the five permanent U.N. Security Council members -- the United States, Russia, China, Britain and France -- and Germany.
But while he maintained a hard line on shipping enriched uranium out of the country for reprocessing, Araqchi told the Iranian Students News Agency the delegation would "address all the fears of the other side."
"We are supposed to enter into a trust-building path with the West," Araqchi said. "In their point of view, trust-building means taking some steps on the Iranian nuclear issue, and in our view, trust is made when the sanctions are lifted."
He told several Iranian news outlets before flying to Geneva his team would present a three-step plan that would secure internationally recognized freedom for Iran's civilian nuclear program because it provided assurances Tehran's nuclear program had only peaceful aims.
The package will lay out the direction Iran would like negotiations to take, he said, without giving package details.
Iranian Foreign Minister Javad Zarif, who is expected to attend the talks' first day, said on Twitter Friday: "We will present our views, as agreed, in Geneva, not before. No Rush, No Speculations Please (of course if you can help it!!!)."
Zarif was expected to have dinner with European Union foreign policy chief Catherine Ashton Monday night.
Ashton, who will direct the talks on behalf of the Western powers, met with U.S. Secretary of State John Kerry to coordinate the Western position Sunday.
Kerry was not expected to participate in the Geneva talks.
The U.S. delegation is expected to be led by Undersecretary of State for Political Affairs Wendy Sherman, the State Department's third-ranking official.
Other members include senior arms control and security adviser James Timbie, principal deputy coordinator for sanctions policy Richard Nephew and Puneet Talwar, the White House National Security Council's senior director for the Gulf States, Iran and Iraq.
The talks will be the first since the election of Iranian President Hassan Rouhani, who has sought to improve relations with the West to pave the way for lifting economic sanctions.
An unidentified Israeli official told The Jerusalem Post Araqchi's refusal to send any of Iran's nuclear material abroad indicated Tehran intended to continue with its weapons program.
Israel has insisted Iran must remove all enriched uranium from its country and dismantle its nuclear weapons facilities.
Jerusalem fears the international community will be assuaged by Tehran's conciliatory tone and, as a trust-building measure, ease some sanctions.
Israeli Prime Minister Binyamin Netanyahu was widely expected to address this when he spoke before Israel's Parliament, the Knesset, at its opening session Monday.