"We don't think statements of deadline on the package are constructive, they are not going to resolve the problem and we decide to give a response next month," Iranian Foreign Ministry spokesman Hamid Reza Asefi said at his weekly press conference. Asefi also rejected allegations that Iran was trying to delay the response.

"There are some ambiguities that need to be discussed with the Europeans, we need to carefully study it and it takes time, so we are not wasting time and this is not our tactic," Asefi said.

He announced that Iran's top nuclear negotiator Ali Larijani and EU foreign policy chief Javier Solana will meet on Wednesday in a bid to remove ambiguities in the package.

Western powers on Thursday exerted mounting pressure on Iran to formally respond in a week to the package which demanded suspension of Iranian uranium enrichment activities.

"We are looking forward to a clear and substantive Iranian response to these proposals at the planned meeting," foreign ministers of the Group of Eight (G8) industrialized countries said in a statement in Moscow.

But Iranian Foreign Minister Manouchehr Mottaki immediately responded in New York that Tehran would not give a response to the proposals before August.

On June 6, Solana presented the package backed by the five permanent members of the UN Security Council plus Germany to Iran. The proposals include both incentives to persuade Iran to suspend uranium enrichment and possible sanctions if Iran does not comply.

Iran has vowed not to give up its legal right to enriching uranium for peaceful end and rejected preconditions for nuclear negotiations.