The US has not had any good intelligence on Osama bin Laden's whereabouts in years, Defence Secretary Robert Gates told ABC News' This Week programme.
Gates also couldn't confirm reports this week that a detainee in Pakistan claimed to have information on where bin Laden, the leader of the Al Qaeda terrorist network, was.
Asked whether Pakistan had done enough to go after bin Laden, Gates said: "Well, we don't know for a fact where Osama bin Laden is. If we did, we'd go get him."
In London this week, Pakistani Prime Minister Yousuf Raza Gilani claimed bin Laden was "not in Pakistan" and insisted that his government's security forces had been "extremely successful" in tackling terrorism within its borders.
President Asif Ali Zardari said in April that bin Laden's whereabouts were unknown and there were unconfirmed reports from local intelligence agencies that he might be dead.
The Al Qaeda leader is believed to be ailing. Some analysts suspect that he is hiding in Pakistan's tribal areas near the border with Afghanistan.