'The claim by an unnamed official is baseless,' said Foreign Ministry spokesman Mohammad Sadiq, who said Islamabad would take action if the US provided it with intelligence to support the statement.

The US official made the comment at a media briefing in Washington Friday, as US Chairman of Joint Chiefs of Staff Admiral Mike Mullen was in Pakistan for talks with top military officials believed to focus on counter-terrorism.

'There is no question that the iconic leaders of Al-Qaeda - (Ayman al-) Zawahiri, bin Laden... are in the tribal areas of Pakistan,' said the official, speaking on condition of anonymity.

'We believe that the Taliban's shura (consultation) council leaders led by Mullah Omar reside in Quetta in Pakistan,' he said, referring to the capital of rugged Baluchistan province.

Mr Mullen's visit followed bloody clashes in the tribal region between Pakistani forces and militants commanded by Al-Qaeda linked tribal Baitullah Mehsud.

A top Al-Qaeda operative Abu Laith al-Libbi was killed in a suspected US missile strike in Pakistan's north Waziristan tribal area early this month. -- AFP