Gates made the comment in an interview to be aired Sunday on ABC's "This Week."
Asked whether he could confirm recent reports that bin Laden had been seen recently in Afghanistan, Gates said "no." Media reports late this week mentioned accounts of unconfirmed bin Laden sightings in recent weeks.
Gates also said the United States' relationship with Afghanistan is going to begin changing in July 2011.
He made the remarks in an interview to be aired Sunday on CBS' "Face the Nation.
When President Barack Obama announced this past week that he was sending 30,000 more troops to Afghanistan, he also set a timeline for starting troop withdrawals in July 2011.
Gates said the U.S. will begin transferring responsibility for security district by district, province by province to the Afghans. And he said that Afghans should understand the nature of their relationship with the U.S. will begin changing then as well. He said the economic, development and political aspects of the relationship will become a bigger part.