Catching bin Laden and other top fugitives remains a priority of the expanding American operation in Afghanistan, but the growing mission is "not about just one or two people," a spokesman said.
"We remain committed to catching these guys. It's pretty much ... just about everything that we do here," Lt. Col. Matthew Beevers said.
But he declined to make any new predictions of when the fugitives might be behind bars.
Beevers insisted the military in Afghanistan was "still confident" of capturing its top targets, but added: "At the end of the day, it's not about just one or two people. It's about ... ensuring that there is stability and security throughout Afghanistan."
Buoyed by the capture of Saddam Hussein in Iraq, the top American commander in Afghanistan, Lt. Gen. David Barno, said in January he was confident bin Laden and Taliban supreme leader Mullah Omar would suffer the same fate this year.
At the time, a spokesman even said the military was "sure" it would catch the two men and Afghan rebel commander Gulbuddin Hekmatyar.
Those remarks, and talk of a spring offensive in Afghanistan by Washington defense officials, triggered speculation bin Laden had been located.
But now the military has followed Defense Secretary Rumsfeld's lead in appearing to lower expectations that a top fugitive would be unveiled during an election campaign in both the United States and Afghanistan.
"Close doesn't count," Rumsfeld said as he stood alongside Afghan President Hamid Karzai during a February visit to Kabul. "I suspect that we'll find that it is accomplished at some point in the future, but I wouldn't have any idea when."
There have been no firm indications of bin Laden's whereabouts since he eluded American and Afghan troops at the battle for the Tora Bora cave complex in eastern Afghanistan in December 2001.
Last month, France's defense minister said French troops had recently helped identify an area in Afghanistan where bin Laden could have hidden, but he provided no specific details.
Barno has vowed to crush insurgents this year in a "hammer-and-anvil" approach with Pakistani forces on the other side of the border.
In a sign of Pakistan's new resolve to crack down on militants, thousands of its troops fought bloody battles with al Qaeda suspects in the South Waziristan border region last month.
Shortly after the siege began March 16, President Gen. Perez Musharraf claimed in a television interview that his men had cornered a "high-value" al Qaeda target, and.
Authorities later backed off those claims, saying instead they had wounded an Uzbek militant with al Qaeda links named Tahir Yuldash. They say they believe Yuldash escaped, possibly through a mile-long tunnel leading out of the battle zone.
Last week, Pakistani forces promised to send thousands of soldiers into a cluster of remote hideouts in a fierce crackdown if tribesmen there do not hand over al Qaeda terrorists by April 20.
The U.S. military insists it will not cross into Pakistan to pursue rebels but has been building up its forces on the Afghan side of the border.
The plan is for the coalition force to reach its largest size yet - 15,500 soldiers, including 13,500 Americans. Two thousand soldiers have been added to the force in recent months, and the military said another 2,000 Marines are arriving in Afghanistan.
Part of the increase is to provide security for badly needed reconstruction projects in former Taliban strongholds, an approach the military hopes will yield better intelligence.
But Beevers would not say where the new Marines will be deployed or whether they will participate in operations to capture al Qaeda leaders.
"We'll make those deployment decisions and locations based on the threat that we see in front of us," he said.