Osama bin Laden has threatened further terrorist attacks on the United States unless America ends its military operations in Iraq and Afghanistan, in an audio tape broadcast on al-Jazeera television.

The Arab satellite station did not verify the authenticity of the ten-minute tape, but will broadcast brief excerpts this evening. The tape is now being investigated by the Pentagon, but analysts believe that it is legitimate and was recorded last month.

The speaker, whose voice closely resembles that on bin Laden's earlier taped messages, offered coalition troops a conditional truce in Iraq and Afghanistan to allow for "construction".

It also gave warning of secret plans for a follow-up attack on America, saying: "The delay in similar operations happening in America has not been because of failure to break through your security measures."

In a statement which suggests the recording was made after July 7, it adds: "The proof of that is the explosions you have seen in the capitals of European nations."

In a direct threat to the American public, he intones: "The operations are under preparation and you will see them in your houses as soon as they are complete, God willing."

In the tape, the speaker refers to public disquiet in the US over the war in Iraq, citing the increasing calls to withdraw troops and stating that Iraq had become a recruiting ground for al-Qaeda.

"Your president is misinterpreting public opinion polls which show that the vast majority of you support the withdrawal of your forces from Iraq," the voice said.

"He [President Bush] disagreed with this desire and said the withdrawal of troops will give the wrong message to the enemy and that it is better to fight them on their ground than on our ground.

"Reality shows that the war against the US and its allies is not just restricted to Iraq as he claims, but Iraq has become a gravitational point and a recruiting ground for qualified mujahidin."

The tape states that al-Qaeda would respond to a military ceasefire in Iraq and Pakistan, where four senior members of the organisation were apparently killed in a US air strike earlier this week.

"We have no objection to responding to this with a long term truce based on fair conditions so we can build Iraq and Afghanistan.

"We are a nation that God has forbidden to lie and cheat. So both sides can enjoy security and stability under this truce so we can build Iraq and Afghanistan, which have been destroyed in this war.

"There is no shame in this solution because it prevents wasting of billions of dollars to merchants of war. Based on what I have said, it is better not to fight the Muslims on their land."

Al-Jazeera regularly carries exclusive interviews with senior al-Qaeda figures, which have brought the station fame and notoriety in equal measure.

Ahmed al-Sheik, the station's editor-in-chief, would not comment on when or where the tape was received. He said the full tape was ten minutes long. The station aired four excerpts it "considered newsworthy," he said, but would not say what was on the remainder.

Henry Crumpton, a US State Department official, said on Tuesday that bin Laden was alive and staying somewhere on the lawless border between Afghanistan and Pakistan.

Although stating that the group's leaders were more concerned with their own survival than mounting another devastating attack, he said: "Al-Qaeda and affiliated groups have a strategic aim of attacking the US homeland. That is their intent, and we believe that they are working toward that. I think also that they intend to attack the UK again, and Europe."

Richard Beeston, Diplomatic Editor of The Times, said that he believed that the tape was likely to be genuine.

"It is very easy for voice patterns to be analysed and, from what I have heard so far, it sounds very much like bin Laden.

"There has been a lot of speculation that bin Laden has died but the US State Department's anti-terrorism unit said recently that he was still alive. The fact that he refers to the attacks on Europe suggests that this was recorded after July 7.

"However, it is hard to take the offer of a 'truce' seriously. The stated objective of al-Qaeda remains the overthrow of pro-Western governments in the Arab world and their replacement with a hardline Islamist regime. Military attacks attributed to al-Qaeda are continuing in Afghanistan, Pakistan and Iraq.

"The other big problem with a truce is that it is no longer clear that bin Laden is in control of al-Qaeda. The network has grown and split into different groups in different countries around the world, so it is unlikely that bin Laden would be able to deliver on such an offer.

"I also don't think negotiation is possible with a man who killed 3,000 people on September 11."

Abdel-Bari Atwan, the London-based editor of the Al-Quds al-Arabi newspaper, said that the tape suggested Bin Laden was attempting to acquire political legitimacy.

"I think he is playing politics here," he said. "He is presenting himself not as a terrorist, a bloodsucker, a man who would like to destroy the world - he also has a political agenda, he is using this terrorism for political ends.

"That is the message he would like to pass: yes we are fighting, but at the same time we are willing to talk, we have our political agenda."

Mustafa Alani, of the Gulf Research Centre in Dubai, told Reuters: "The value is not what he’s saying, the value is that he is still alive. Again, I wonder why it’s not a video. Possibly he’s not in good enough health."

Bin Laden's most recent video appearance came four days before the US election in late 2004, in which he gave details the September 2001 attacks and repeatedly insulted President Bush.

His last broadcast audiotape was in December 2004 in which he appointed Abu Musab al-Zarqawi as al-Qaeda’s leader in Iraq.

Explore World News

• World Agenda

• Iraq News

• US & Americas News

• Europe News

• Middle East News

• Afghanistan News

• Asia News

• Africa News

• Ireland News

Times Recommends

• It’s only Brits who don’t appreciate me, says Blair
• Party’s over for Greek graspers
• White House tightens security for Xmas marathon