The clerical regime's top nuclear negotiator, Hassan Rohani, warned that long-term nuclear negotiations could not continue without Iran first resuming uranium work -- the focus of international fears the country is seeking to build nuclear weapons.

"We cannot continue the negotiations with the Europeans without having resumed some of our activities," Rohani told state television, adding Iran's decision to resume conversion of uranium -- a precursor to enrichment -- was "still valid."

"We are in favor of negotiations. We can negotiate for months, but we cannot negotiate under the present conditions," Rohani argued, repeating the demand to resume activities that were suspended in November 2004 as part of a deal with Britain, France and Germany.

Iran announced earlier that it was postponing a restart of work at Isfahan, a move that would have violated the accord, following appeals from the so-called EU-3 and their offer of four-way talks.

The three European nations also warned Iran that it could wind up on the desk of the UN Security Council.

"We are in favor of the principle of negotiating," Rohani said, adding that "the fact that the resumption of our activities will be delayed by several days is not a problem."

"Last chance for Europe"

Speaking in Vienna, French Foreign Minister Michel Barnier confirmed that he, German Foreign Minister Joschka Fischer and British Foreign Secretary Jack Straw would meet Iranian authorities in the coming days.

Iranian media reports said the meeting would take place in either Geneva or Brussels. "The coming days will be the last chance for the Europeans," Iranian foreign ministry spokesman Hamid Reza Asefin told reporters. "With or without an agreement, we will restart our activities."

"The Security Council does not worry Iran," Asefi said, but acknowledged that Iran had also received appeals from South Africa, Malaysia and UN Secretary General Kofi Annan -- who telephoned Iran late Saturday -- to hold more talks.

The EU has offered Iran a package of incentives in return for "objective guarantees" it will not develop weapons -- hoping to strike a deal similar to that which the United States and Britain reached with Libya.

Defiant message

But Iran has expressed frustration with the pace of the negotiations, which remain deadlocked given Iran's refusal to abandon fuel cycle work.

The stand-off worsened after the EU-3 last month rejected an Iranian proposal to begin a phased resumption of enrichment. Iran complained the talks were being deliberately dragged out to keep the freeze in place.

Iran's hardline parliament also took a defiant stand Sunday, passing a bill that obliges the government to "guarantee" the Islamic republic's production of its own nuclear fuel.

The bill, entitled "acquiring nuclear technology for peaceful purposes" was the latest move by right-wingers seeking to send a defiant message in the face of mounting international demands that Iran abandon its nuclear fuel programme altogether.

Deputies had already begun voting on the bill in October 2004, and it has been seen largely as a symbolic gesture. After the vote, deputies in the Majlis broke out into chants of "Death to America."

One hardline MP, Hasan Kamran, said the bill "will send a message to world oppressors the US and its European footsoldiers."