Iran's delegation will be led by Amir Hossein Zamani-Nia, director of the foreign ministry's international political affairs department, said Hossein Mussavian, spokesman for Iran's team for nuclear negotiations.

He said Britain, France and Germany would be represented by officials of their foreign ministries.

On Tuesday, the foreign ministers of Britain and Germany issued a joint warning to Iran to address international worries about its nuclear program, serving notice that Tehran must take action immediately.

"Iran has yet to give us the confidence we need about its intentions," British Foreign Secretary Jack Straw said following talks in London with his German counterpart Joschka Fischer.

And Britain's International Security Minister Denis MacShane said Iran must "act decisively" to allay concerns raised by the International Atomic Energy Agency (IAEA) about its alleged intention to acquire nuclear weapons.

"Confidence cannot be restored unless Iran agrees to suspend its fuel cycle activity, including all centrifuge work and uranium conversion," MacShane told a meeting in London.

In September the IAEA called on Iran to "immediately" widen its suspension of uranium enrichment to include all uranium enrichment-related activities, which it has so far refused to do so.

Iran faces a November 25 deadline, after which it risks being referred to the Security Council for further action.

But a top Iranian nuclear official reiterated Tuesday that the Islamic republic wanted to enrich uranium to provide fuel for its future nuclear power plants.

"We are not saying we are refusing Westerners offers to provide us with nuclear fuel, but we want also to produce our own nuclear fuel ... as well as buying what we lack from the West," Iranian Atomic Energy Organizationchief Gholamreza Aghazadeh said on state television.

He also denounced the "politicizing" of the Iranian nuclear case, declaring that Iran did not have "any non-peaceful nuclear activities."