Pakistan is dismissing an assertion by a U.S. official that the leaders of al-Qaida and the Taliban are operating out of that country's remote tribal areas.
A Foreign Ministry spokesman, Mohammad Sadiq, stressed that Islamabad would take action if Washington provided intelligence to back up the claim.
A senior U.S. official in Washington told reporters Friday that al-Qaida leader Osama bin Laden, his deputy Ayman al-Zawahri and others were operating out of Pakistan's tribal areas, near the Afghan border.
The official, who spoke on the condition of anonymity, said Taliban leader Mullah Omar was residing in Quetta, the capital of Pakistan's Baluchistan province, and that he was directing insurgency operations in Afghanistan from there.
Pakistani President Pervez Musharraf rejected a similar assertion about Mullah Omar's whereabouts last year.
Pakistan is a key U.S. ally in fighting terrorism, but it has been criticized by some Afghan and U.S. officials for harboring extremists who carry out attacks in Afghanistan.
Pakistan denies that charge and says it has shown its commitment to fighting terrorism by deploying thousands of troops along the Afghan border.
Some information for this report was provided by AFP and Reuters.