Iran has rejected the United States' conditional offer for direct talks. The Iranian foreign minister said that while Iran is open to the idea of dialogue with the United State, it will not suspend its nuclear work.

Iranian Foreign Minister Manouchehr Mottaki said Iran is open to talks with the United States, but he rejected the U.S. precondition that it must quit enriching uranium first.

"We welcome dialogue in a just and unbiased atmosphere, but we will not negotiate on our undeniable and legitimate rights," he said.

Secretary of State Condoleezza Rice said Wednesday the United States would be willing to talk with Iran if it suspends its uranium enrichment and reprocessing.

The U.S. offer to negotiate is being seen as a major policy shift.

It has been cautiously welcomed by Russia and China, which have ties to Tehran and have opposed the use of sanctions.

The United States has had no high-level talks with Iran for more than 25 years. The two countries formally broke off relations in 1980, after the seizure of the American embassy in Tehran in 1979.

Iran says it has a right under international law to build a peaceful nuclear program to produce electricity. The United States and a number of European countries believe Iran is secretly trying to build a nuclear weapon.

World powers are meeting in Vienna to finish up plans for the package of economic and diplomatic incentives aimed at persuading Iran to give up its nuclear program. The proposal is reported to include a European-built light-water reactor, as well as sanctions if Iran refuses to abandon its enrichment work.

Diplomats from the five permanent U.N. Security Council members plus Germany have been haggling over the details of the package for weeks.