Mottaki made the declaration on the sidelines of a welcoming ceremony of Armenian President Robert Kocharian who is in Iran ona two-day official visit..

"There will be no negotiations between Larijani and Solana today," the minister was quoted as saying, without giving further details.

Larijani and EU foreign policy chief Solana had been due to explore whether Iran is ready to respond to a package agreed on by the five permanent members of the UN Security Council plus Germany over its nuclear issue, which demands Iran suspend uranium enrichment in return for economic and political incentives.

Meanwhile, an EU statement said that Larijani would meet Solana on Thursday and on July 11.

"I was surprised to hear that Dr. Ali Larijani has decided at the last minute to postpone his trip to Brussels as previously agreed with him to take place today," Solana said in the statement.

"I have just spoken to Dr. Larijani on the phone and we decided to meet tomorrow in Brussels, then continue the discussions on July 11," the statement added.

Western powers have recently mounted pressures on Iran, asking the country to formally respond by mid July to the six-nation package.

During a Moscow meeting last Thursday, foreign ministers of the Group of Eight industrialized countries urged Iran to give "a clear and substantive response" to the package at the upcoming meeting between Larijani and Solana.

But Larijani said on Monday that he would not give a response to the package in his meeting with Solana, saying it was not "reasonable" for the West to demand a suspension of Iran's nuclear program.

A senior U.S. official said on Monday that Iran must respond to the offer by July 12 or it would face action by the UN Security Council.

"If Iran has not responded by July 12, then I think the pressure will be enormous on the Iranians from all the international community," said U.S. Undersecretary of State for Political Affairs Nicholas Burns.

On June 6, Solana presented Iran with the package, which includes both incentives aimed at persuading Iran to suspend uranium enrichment and possible sanctions if Iran does not comply. The United States has accused Iran of secretly developing nuclear weapons under a civilian front, a charge categorically denied by Tehran.