Barack Obama has signalled that he is operating under the assumption that Osama Bin Laden is still alive, despite remarks by Pakistan's President saying intelligence service believes the Al-Qaeda leader has died.
At a town hall meeting in the central US state of Missouri, Obama yesterday defended his decision to send thousands more troops to Afghanistan to battle a bloody insurgency despite objections from fellow Democrats.
The President, speaking to a crowd marking his first 100 days in office, said he understood the concerns.
"But as commander-in-chief it is my responsibility to make sure that bin Laden and his cronies are not able to create a safe haven within which they can kill another 3,000 Americans or more," Obama said in an apparent reference to those killed in the September 11, 2001 attacks on the United States blamed on Al-Qaeda.
"That's an obligation that I have."
Obama also reiterated his administration's position that Al-Qaeda and the Taliban "are the single most direct threat to our national security interests."
The President's comments seemed to be at odds with those made Monday by Pakistani President Asif Ali Zardari.
"The Americans tell me they don't know, and they are much more equipped than us to trace him. And our own intelligence services obviously think that he does not exist any more, that he is dead," Zardari told reporters.