Iran will not give up its right to enrich uranium, a senior Iranian official said today.
"Suspending enrichment is not negotiable. . . . Depriving Iran of its right cannot be on offer," Gholamhossein Elham, the government spokesman, told a press conference.
His comments come as major powers prepare to submit an upgraded package of incentives to try to coax Tehran into halting the work.
Iran has agreed to a visit by EU foreign policy chief Javier Solana to submit the package of incentives, in exchange for a full suspension of uranium enrichment.
The five permanent members of the U.N. Security Council - the United States, France, Britain, China and Russia - and Germany, known as the P5+1, offered a package to Iran in 2006 that also required Iran to halt enrichment.
Tehran rejected those proposals and the latest package is an enhanced version.
Mr Elham said no date had been set for Solana's trip. A Western diplomat said Mr Solana was expected to visit Iran on June 14th.
Iran has handed over what it calls a "proposed package for constructive negotiations". But it ignores the West's main demand, which is suspending enrichment.
The UN Security Council has imposed three sanctions resolutions on Iran for refusing to halt the sensitive activity. Iran, the world's fourth largest oil producer, says its enrichment activity is aimed at generating electricity.