Updated

President Bush was told more than a month before the Sept. 11 attacks that Al Qaeda (search) had reached America's shores, had a support system in place for its operatives and that the FBI had detected suspicious activity that might involve a hijacking plot.

Since 1998, the FBI (search) had observed "patterns of suspicious activity in this country consistent with preparations for hijackings or other types of attacks," according to a memo prepared for Bush and declassified Saturday.

White House aides and outside experts said they could not recall a sitting president ever publicly releasing the highly sensitive document, known as a PDB, for presidential daily briefing.

The Aug. 6, 2001 PDB referred to evidence of buildings in New York possibly being cased by terrorists.

The document also said the CIA (search) and FBI were investigating a call to the U.S. embassy in the United Arab Emirates in May 2001 "saying that a group of [Usama] bin Laden supporters was in the U.S. planning attacks with explosives."

The commission investigating the Sept. 11 (search) attacks, which killed nearly 3,000 people in New York City, Washington and Pennsylvania, asked the White House to declassify the document at its meeting Thursday. It is significant because Bush read it, so it offers a window on what Bush and his top aides knew about the threat of a terrorist strike.

The PDB made plain that bin Laden (search) had been scheming to strike the United States for at least six years. It warned of indications from a broad array of sources, spanning several years.

Democratic and Republican members of the 9-11 commission saw the document differently.

Democratic commissioner Bob Kerrey, a former senator from Nebraska, said the memo's details should have given Bush enough warning to push for more intelligence information about possible domestic hijackings.

"The whole argument the government used that we were focusing overseas, that we thought the attack was coming from outside the United States — this memo said an attack could come in the United States. And we didn't scramble our agencies to that," he said.

Richard Ben-Veniste, a Democratic commissioner and former Watergate prosecutor, said the memo calls into question national security adviser Condoleezza Rice's assertion Thursday that the memo was purely a "historical" document.

"This is a provocative piece of information and warrants further exploration as to what was done following the receipt of this information to enhance our domestic security," he said.

Senior administration officials said Bush saw more than 40 mentions of Al Qaeda in his daily intelligence updates during the first eight months of his presidency. The CIA prepared the document "in response to questions asked by the president about the possibility of attacks by Al Qaeda inside the U.S," one said.

But the senior officials refused to say what Bush's response to the memo was.

Republican commissioner James R. Thompson, a former Illinois governor, said the memo "didn't call for anything to be done" by Bush.

The memo's details confirm that the Bush administration had no specific information regarding an imminent attack involving airplanes as missiles, Thompson said.

"The PDB backs up what Dr. Rice testified to. There is no smoking gun, not even a cold gun," he said.

"Clandestine, foreign government, and media reports indicate bin Laden since 1997 has wanted to conduct terrorist attacks in the U.S.," the memo to Bush stated. Bin Laden implied in U.S. television interviews in 1997 and 1998 that his followers would follow the example of World Trade Center bomber Ramzi Yousef and "bring the fighting to America."

After President Clinton launched missile strikes on bin Laden's base in Afghanistan in 1998 in retaliation for bombings of U.S. embassies in Kenya and Tanzania that killed 231 people, "bin Laden told followers he wanted to retaliate in Washington," the memo said.

The memo cited intelligence from other countries in three instances, but the White House blacked out the names of the nations.

Efforts to launch an attack from Canada around the time of millennium celebrations in 2000 "may have been part of bin Laden's first serious attempt to implement a terrorist strike in the U.S.," the document stated.

Convicted plotter Ahmed Ressam, who was caught trying to cross the Canadian border with explosives about 60 miles north of Seattle in late 1999, told the FBI that he alone conceived an attack on Los Angeles International Airport, but that bin Laden lieutenant Abu Zubaydah "encouraged him and helped facilitate the operation," the document said. Ressam is still awaiting sentencing after agreeing to testify in other terrorism cases.

Zubaydah was a senior Al Qaeda planner who was captured in Pakistan in March 2002.

Al Qaeda members, some of them American citizens, had lived in or traveled to the United States for years, the memo said.

"The group apparently maintains a support structure that could aid attacks," it warned.

The document said that "some of the more sensational threat reporting" — such as an intelligence tip in 1998 that bin Laden wanted to hijack aircraft to win the release of fellow extremists — could not be corroborated.

One item in the memo referred to "recent surveillance of federal buildings in New York." A White House official speaking on condition of anonymity said that was a reference to two Yemeni men the FBI interviewed and concluded were simply tourists taking photographs.

On May 15, 2001, a caller to the U.S. embassy in the United Arab Emirates warned of planned bin Laden attacks with explosives in the United States, but did not say where or when.

The CIA reported the incident to other government officials the next day, and a dozen or more steps were taken by the CIA and other agencies "to run down" the information from the phone call, senior administration officials said Saturday evening.

One official said references to Al Qaeda in prior presidential briefings "would indicate 'they are here, they are there' in various countries and the CIA director would tell the president what was being done to address "these different operations."