Pakistan's north-western region, with its porous border with Afghanistan, has long been suspected as the hiding place for bin Laden.

Panetta also said the CIA had increased the number of officers and agents in Pakistan who were providing information to help attack the al-Qaeda network there.

Message to Obama

In a tape broadcast by Al Jazeera last week, bin Laden accused Barack Obama, the US president, of following the policy of his predecessor, George Bush, in "antagonising Muslims".

In a message shortly after Obama arrived in Saudi Arabia last Wednesday, bin Laden also said the president had inflamed hatred toward the US by ordering Pakistan to crack down on fighters in the Swat Valley.

The US has blamed bin Laden and al-Qaeda for a host of terror attacks, most notably the September 11 attacks in 2001 that killed almost 3,000 people.

It is offering a $25million bounty for information leading to his capture.