Updated

When President Bush took office in January 2001, the White House was told that Predator drones (search) had recently spotted Usama bin Laden as many as three times and officials were urged to arm the unmanned planes with missiles to kill the Al Qaeda (search) leader. But the administration failed to get drones back into the Afghan skies until after the Sept. 11 attacks later that year, current and former U.S. officials say.

Top administration officials discussed the mission to kill bin Laden as late as one week before the suicide attacks on New York and Washington, but they had not yet resolved a debate over whether the CIA or Pentagon should operate the armed Predators and whether the missiles would be sufficiently lethal, officials told The Associated Press.

In the month before that meeting, the Pentagon and CIA successfully tested an armed Predator on at least three occasions -- including once when it destroyed a mock-up home resembling an Afghan structure bin Laden supposedly used, the officials said.

The disappearance in 2001 of U.S. Predators from the skies over Afghanistan is discussed in classified sections of Congress' report into pre-Sept. 11 intelligence failures and is expected to be examined by an independent commission appointed by the president and Congress, officials said.

After the Sept. 11 attacks, the CIA put the armed drones into the sky within days -- and they soon played an important role in one of the early successes of the war on terror.

In November 2001, a drone helped confirm a high-level Al Qaeda meeting in Kabul, Afghanistan, and joined in an attack that killed bin Laden military chief Mohammed Atef (search), according to officials familiar with the attack.

Nearly a dozen current and former senior U.S. officials described to AP the extensive discussions in 2000 and 2001 inside the Clinton and Bush administrations about using an armed Predator to kill bin Laden. Most spoke only on condition of anonymity, citing the classified nature of the information. Two former national security aides also cite some of the discussion inside the Bush White House in a recent book they published on terrorism.

The officials said that within days of President Bush taking office in January 2001, his top terrorism expert on the National Security Council, Richard Clarke (search), urged National Security Adviser Condoleezza Rice (search) to resume the drone flights to track down bin Laden, citing the successes of late 2000.

The drones were one component of a broader plan that Clarke, a career government employee, had devised in the final days of the Clinton administration to go after Al Qaeda after the October 2000 bombing of the USS Cole (search). Clinton officials decided just before Christmas 2000 to forward the plan to the incoming Bush administration rather than implement it during Clinton's final days, the officials said.

Propeller-driven Predators first flew for the military in July 1995 over Bosnia, but early versions couldn't transmit high-quality live video. The Air Force gradually improved camera resolution and first successfully fired a Hellfire missile from a Predator on Feb. 16, 2001.

By summer 2001, the Predator was armed for another test in the Nevada desert that destroyed a mock-up of a home bin Laden was suspected of using in Afghanistan, Clarke told executives in a recent speech at a technology conference.

Some U.S. officials, however, worried that an anti-tank missile with just a 27-pound warhead might not be powerful enough to kill everyone inside a building, and the military worked to modify the warhead to be more lethal, officials said.

Cruise missile warheads, by comparison, weigh 1,000 pounds, and traditional bombs typically range from 500 to 2,000 pounds.

Hellfire missiles were attached to the drone after unarmed Predators flown by the CIA from Uzbekistan to Afghanistan spotted a man that several U.S. intelligence analysts believed was bin Laden, or his trademark Japanese truck, as many as three times in September and October 2000, the officials said.

"They were operating them before the United States military was involved ... and doing a good job," Defense Secretary Donald Rumsfeld has said, explaining why CIA operated the armed drones in Afghanistan. "And so rather than changing that, we just left it."

During the fall 2000 sightings, the United States was unable to launch a strike with submarine-based cruise missiles in time to kill bin Laden, officials said.

With powerful winter winds over the mountains affecting the drones' flights, the Predators were taken out of action in Afghanistan after October 2000 and retrofitted with weapons. One was repaired after it crashed on landing, sparking debate whether CIA or the Pentagon would pay the damage. Officials said they planned to put the drones back into the air as early as March 2001 after the winds subsided.

Of 11 successful Predator flights sent across the mountains from Uzbekistan to Afghanistan in September and October 2000, three spotted a person that several U.S. intelligence analysts concluded was bin Laden.

"Different people came to different conclusions. You couldn't see facial characteristics. But there were several who concluded it was bin Laden," one senior U.S. official said, explaining those assessments were based on size, clothing, a beard and human intelligence.

The Predators, however, were not put back in the air before Sept. 11.

Officials said the delay was due in part to arming the Predator with enough lethal force and resolving the debate over which agency was legally and practically best equipped to carry out an attack.

Another official said the CIA was opposed in the interim to running too many unarmed Predator flights for fear that would lead Afghan and Al Qaeda leaders to be on the lookout for the drones and to flee sites before bombs or missiles could be launched.

"The agency wanted to keep it under wraps and catch them by surprise once they were armed," the official explained.

That official noted that during one of the unarmed 2000 Predator flights, MiG jets were scrambled by Afghanistan's then-ruling Taliban government and they tried unsuccessfully to shoot down one of the drones. Another time, Al Qaeda operatives spotted a drone and pointed to it, officials said.

A former administration official said U.S. officials watched some of the Predator missions live on a television screen inside CIA headquarters, including the one in which Taliban pilots roared past.

After Clarke's briefing in January, the drone plan was discussed again in late April by national security deputies and the test on the mock-up of bin Laden's home was conducted in July. A Bush administration official said Rice was generally supportive of the idea as part of a broader strategy.

At a White House meeting of Bush's national security principals on Sept. 4, 2001, senior officials discussed several ideas, including use of the drones, as they finalized a plan to accelerate efforts to go after Al Qaeda amid signs of a growing threat of a domestic attack.

Among those present were Rice, CIA Director George Tenet, soon-to-be chairman of the Joint Chiefs of Staff Gen. Richard Myers, Deputy Defense Secretary Paul Wolfowitz and Clarke, then Bush's anti-terrorism chief inside the White House.

Though CIA had operated the unmanned Predators in Afghanistan in 2000, Tenet expressed strong reservation about his agency running the armed drones for an attack mission, suggesting it was the purview of the military, according to officials who witnessed or were briefed about the meeting.

"Generally it was understood [inside CIA] that aircraft firing weapons is the province of the military. This was a discussion about what the appropriate agency was to carry out the mission, but it was not a matter of the technology," said one official familiar with Tenet's comments at the meeting.

Defense officials suggested they be given an objective -- kill bin Laden -- and be left to make their own decisions about whether to use a drone or other weapons like cruise missiles and B-1 bombers, officials said.

Targeting bin Laden was legally permitted under secret orders and presidential findings that Clinton had signed.

Officials at the Sept. 4 meeting put off recommending the armed drone as a solution. Instead, they finalized a series of other measures to rout Al Qaeda from its base in Afghanistan, including re-arming the rebel Northern Alliance.

Those recommendations were being forwarded from Rice to Bush when the Sept. 11 hijackers struck, officials said.