Investigators have found no evidence Iraq aided al Qaeda attempts to strike the United States, a commission investigating the September 11, 2001, attacks said on Wednesday in a report that undermines Bush administration arguments for war.
The report by commission staff said al Qaeda leader Osama bin Laden had met with a senior Iraqi intelligence officer in 1994 and had explored the possibility of co-operation, but the plans apparently never came to fruition.
US President George W. Bush and Vice President Dick Cheney this week reiterated pre-war arguments that an Iraqi connection to al Qaeda, which is blamed for the September 11 attacks, represented an unacceptable threat.
However, the commission said in a staff report, "We have no credible evidence that Iraq and al Qaeda co-operated on attacks against the United States."
"There is no convincing evidence that any government financially supported al Qaeda before 9/11 - other than limited support provided by the Taleban after bin Laden first arrived in Afghanistan," it added.
Counter-terrorism officials from the FBI and CIA testifying at Wednesday's hearing said they agreed with the staff report's conclusion.
The report was issued at the start of the commission's final two days of public hearings into the hijacked-plane attacks, which killed nearly 3,000 people.
The hearings were called to find out how the United States failed to prevent the attacks and what it can do now to improve security.
The report stood in contrast to comments this week by Vice President Dick Cheney, who said that ousted Iraqi leader Saddam had "long-established ties" to al Qaeda.
Bush, asked on Tuesday about Cheney's comments, cited the presence in Iraq of Abu Musab al-Zarqawi as "the best evidence" of an Iraqi connection to al Qaeda.
The president said on Wednesday Saddam had "sheltered terrorist groups" and America was safer because of his ouster.
Although Cheney and other officials had suggested Iraq might have played a direct role in the September 11 attacks, Bush acknowledged after the war that there was no evidence of this.
A separate draft report by the commission also describes confusion in the Pentagon on the day of the attacks, the New York Times reported. It said Pentagon procedures were "unsuited in every respect" for the attacks, and unprepared officials responded with a "hurried attempt to create an improvised defence."
Furthermore, the newspaper quoted commission chairman Thomas Kean as saying "there was a lot of chaos" in the White House response.
It said commission members wanted to know why Bush was allowed to continue meeting with Florida schoolchildren after the attacks were known, and why Bush hop-scotched around the country on Air Force One before returning to Washington.
In a report entitled "Overview of the Enemy," the commission said al Qaeda has changed drastically and become decentralised since the September 11 attacks, but it still helps regional networks and will keep trying to strike the United States to inflict mass casualties.
"Al Qaeda remains extremely interested in conducting chemical, biological, radiological or nuclear attacks," said the report.
Al Qaeda's ability to conduct an anthrax attack is one of the most immediate threats, it said. Al Qaeda may also try to attack a chemical plant or shipment of hazardous materials, or to use industrial chemicals as a weapon.
The report said al Qaeda may modify "traditional tactics" to prevent detection.
The CIA estimates al Qaeda spent $30 million a year before September 11 for terror operations, to run the training camps and contribute to Afghanistan's Taleban militia.
While it found no convincing evidence of government support, the panel said Saudi Arabia provided "fertile fund-raising ground" for al Qaeda.
A second panel report on Wednesday said there was no evidence Princess Haifa al-Faisal, the wife of Saudi ambassador to Washington Prince Bandar bin Sultan, had contributed any funds to the conspiracy.
The FBI has examined whether some of her charitable donations ended up with the hijackers.