President Bush today accused Iran of dragging its feet over whether to accept an internationally-agreed package of incentives in return for suspending its uranium enrichment programme.

At a summit in Vienna, Mr Bush warned Iran that it was not reasonable to wait until late August before replying to the offer.

President Mahmoud Ahmadinejad of Iran said earlier today that it would be another couple of months before his country got round to responding to the proposals, delivered in person in Tehran by the EU's chief diplomat Javier Solana two weeks ago.

"We are studying the proposals. Hopefully, we will present our views about the package by mid-August," Mr Ahmadinejad told a crowd in western Iran in a speech broadcast live on state television.

The deal includes the offer of civilian nuclear technology, and a lifting of sanctions on the sale to Iraq of vital aircraft spare parts, as well as the chance for Iran to negotiate face to face with the US for the first time in nearly three decades.

In return, Iran is expected to halt its work on enriching uranium which many foreign powers believe is the precursor of a nuclear weapons programme.

At the annual US-European Union summit in Vienna today, Mr Bush was noticeably unimpressed by Mr Ahmadinejad's latest pronouncement, and disinclined to make further concessions.

"We’ll come to the table when they verifiably suspend. Period," Mr Bush said.

"August 25 seems an awful long time for an answer to a reasonable proposal. It shouldn't take the Iranians that long to analyse what is a reasonable deal.

"In the past I have said (that they should respond within) weeks, not months, and I believe that that is the view of our partners."

The major powers have set an informal deadline of mid-July, when the G8 summit is planned.

Western diplomats believe that Iran’s hesitation to respond may be a stalling manoeuvre, aimed at buying time to expand its nuclear fuel enrichment programme and make it a fait accompli.

Diplomats and analysts in Tehran say, however, that the delay is more a sign of debate within the complex and multi-layered Iranian power structure over how to respond.

Some leading figures, including the country's spiritual leader, have called for an outright rejection, while others have said that parts of the package are acceptable but certain points should be changed.

Iran maintains that its haste to enrich uranium in defiance of international pressure is solely to provide electricity for its economy.

Mr Bush has warned that if Iran rejects the deal it can expect UN Security Council action and progressively stronger political and economic sanctions.

The President was put under pressure by reporters to justify the parts of his foreign policy which are unpopular in Europe, such as the invasion of Iraq, rendition of terror suspects, and the Guantanamo Bay prison camp. He appeared conciliatory in his responses.

"I would like to end Guantanamo, I would like it to be over with. One of the things we will do is we will send people back to their home countries," said Mr Bush.

"We have about 400 people still there, mainly from Saudi Arabia, Afghanistan and Yemen... some of them are awaiting trial in the US. They are cold-blooded killers and they will murder someone if they are let out on the streets.

"I understand the concerns of the leaders and the European people about what Guantanamo says, I share with them my deep desire to end this programme, but we will not let out on the street people who will do you harm."

In response to a question about the US practice of rendition - the kidnapping of terror suspects for questioning in foreign jails - Mr Bush made an impassioned plea for understanding over his so-called war on terror.

He retorted: "Look, people didn't agree with my decision on Iraq. I understand that. For the United States, September 11 was a moment - for others, it was something else. I fully understand that the longer we go away from September 11, the more people will forget the lessons of September 11, but I will not forget.

"I understand some of the decisions I made were controversial, but I would defend them. I believe it was right to encourage democracy in the Middle East... I don't govern by focus group, I do what I think is right. I don't think it is right to condemn people to tyranny, among those of us who live in a free society."

Charles Bremner, Paris correspondent for The Times, who attended the press conference, said that the summit atmosphere was more upbeat than in previous years. "We have Bush saying that he understands Europe's concerns, but he was trying to do the right thing. The mood music of the summit was very positive," he said.

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