Iran rejects West's timetable for talks

"The timetable drawn up by other people has no influence on what we do," he told a news conference in Madrid.

Larijani said Tehran had been working seriously on the offer made on June 6 by six western powers, France, Britain, Germany, the United States, Russia and China, but "needed to devote sufficient time (to it)".

"We view this proposition in a positive light but there are doubts about it which we have to clarify through dialogue," he said.

"I see no reason to be pessimistic," he continued, adding, "we do not need to be given a time limit to respond ... that does not make sense."

"If negotiation is to take place it needs to be in the language of negotiation," he stated in response to questions about western pressure on Iran to respond quickly.

Iran is facing mounting international pressure to show ahead of the Group of Eight (G8) summit on July 15-17 that it is ready to accept the offer from the six powers.

On Thursday the European Union, Russia and the United Nations' nuclear watchdog, the IAEA, all reiterated appeals for Tehran to respond soon, and the United States again brandished the threat of UN Security Council sanctions.

On Friday Larijani held discussions in Madrid with Spanish Prime Minister Jose Luis Rodriguez Zapatero and Foreign Minister Miguel Angel Moratinos. The latter stressed that Spain supported the international offer and hoped Iran would "respond promptly" to the proposal, which Madrid supported, according to the foreign ministry.