"If he has a watch, he should be looking at it because the clock is ticking. He will be caught," Joseph Cofer Black, the U.S. State Department coordinator for counterterrorism, told private Geo television network.
Asked if concrete progress had been made during the last two months, when Pakistan has arrested dozens of terror suspects including some key al Qaeda operatives, Black said, "Yes, I would say this."
Black, who briefed a group of Pakistani journalists after talks with officials here Friday, said he could not predict exactly when bin Laden and other top al Qaeda fugitives would be nabbed.
"What I tell people, I would be surprised but not necessarily shocked if we wake up tomorrow and he's been caught along with all his lieutenants. That can happen because of the programs and infrastructure in place," he told Geo.
Bin Laden and his top associate Ayman al-Zawahri are believed to be hiding some place along the long and rugged border between Pakistan and Afghanistan. Officials have divulged no solid intelligence on their exact whereabouts, and it's not clear if they have any.
Pakistan is a key ally of the United States in its war on terror, and Black's visit comes weeks after Pakistani security forces captured Ahmed Khalfan Ghailani, a Tanzanian wanted for the 1998 U.S. embassy bombings in east Africa, and Mohammed Naeem Noor Khan, a Pakistani computer expert allegedly linked to al Qaeda operatives around the world.
The arrests led to a terror warning in the United States, and arrests in Britain and the United Arab Emirates.
Black attended a meeting of the Pakistan-U.S. Joint Working Group on Counterterrorism and Law Enforcement in Islamabad on Thursday and Friday.
During the talks, Pakistan asked U.S. officials for more helicopters, surveillance and communications equipment to help Pakistani forces guard border areas near Afghanistan "more efficiently," a Pakistani official at the talks said.
"We got a positive response from the American officials," said the official, who spoke on condition of anonymity.
Pakistan has deployed about 70,000 troops along the Afghan border and conducted several military operations this year in its lawless tribal regions against al Qaeda suspects and their local supporters.
Black hailed Pakistan's efforts in counterterrorism, despite criticism from Western officials who say that elements of the former ruling Taliban regime in Afghanistan still operate inside Pakistan.
"In terms of national programs and effectiveness, I would put Pakistan up against anyone else ... If you look at the arrest they have made, the information they have developed and the lives that have been saved, Pakistan is doing a great job," he said.
He added, however, that, "you can always do more."