Iranian President, Mahmud Ahmadinjed, told a crowd in western Iran that they may not give an answer on the package, which was presented on the 6th of June, until August the 22nd.
US President George W. Bush, responding to Mr Ahmadinjed’s timetable after a summit in Vienna with European leaders, said he expected Iran to give an answer earlier than that.
In Vienna European diplomats have said the EU expects an answer from Iran to their offer by June the 29th.
Mr Ahmadinejad's statement prompted immediate telephone consultations between the foreign ministries of Britain, China, France, Russia, the United States, the
UN Security Council permanent members, plus Germany over a unified stance to
the delay.
Iranian Foreign Minister Manouchehr Mottaki, on a visit to Rome, came back with a message to Mr Bush that Iran would not be rushed.
Deadline debate
"When (European Union foreign policy chief) Javier Solana gave us his suggestions on June 6 no time limit was set", he told Italian television.
"It seems like an awful long time for a reasonable proposal," President Bush said of the Iranian date. "It shouldn't take the Iranians that long to analyse what is a reasonable deal."
"The only undertaking required from Iran is not to divulge the content of the offer as long as an agreement has not been reached and we respect that commitment," Mr Mottaki said.
The proposal had "many ambiguities. It is right for Iran to study the document seriously and precisely until August 22," he said.
Earlier Iran had dismissed a warning by Bush of stronger sanctions if Tehran did not bow to international demands over its nuclear program
"Bush's language is not acceptable and does not fit in with our cooperation with Europe," foreign ministry spokesman Hamid Reza Asefi was quoted as saying by the official news agency IRNA.
Mr Bush has recently turned up the pressure on Tehran, warning of "progressively stronger political and economic sanctions" if it refused to freeze sensitive nuclear activities in return for talks.
Mr Bush signalled that suspending uranium enrichment and reprocessing was not negotiable.