The official further said that Osama bin Laden, his deputy Ayman al-Zawahri and others were operating out of Pakistan's Federally Administered Tribal Areas (FATA). "We believe that the Taliban's shura (consultation) council leaders led by Mullah Omar reside in Quetta in Pakistan," the official said, referring to the capital of rugged Balochistan province bordering Afghanistan.
"They run the shura council, they run the strategic command and control out of the city of Quetta," said the official, speaking on condition of anonymity.
The United States has placed a multi-million dollar bounty on the head of Omar, whose Taliban ruled Afghanistan from 1996 to 2001.
The US official, speaking at a formal media briefing, also said that the United States had seen clear links between the insurgency in Afghanistan and Pakistan through the Pashtun group, an ethnic-minority numbering some 39 million along the troubled Pakistan-Afghanistan border.
"We also know that there are very clear Pashtun tribal links up through the FATA, especially in north and south Waziristan, where Pashtuns who live in Pakistan are supporting Pashtuns, who are fighting in Afghanistan," he said.
"In some cases, they are the one and same people -- they live in Pakistan, they commute to the fight, they fight for a while in Afghanistan and retreat back into safe haven inside Waziristan," the official said.
Meanwhile, Pakistan has rejected the U.S. official's assertion that al Qaeda leader Osama bin Laden and Taliban leader Mullah Omar are operating from Pakistani territory.
Foreign Ministry spokesman Mohammad Sadiq said if the US official had information on the whereabouts of the wanted militants he should tell Pakistan.
"If there is any actionable intelligence it should be shared with the Pakistan Government so that they can be neutralised," The News quoted Sadiq, as saying.
"You don't talk to the media if you have information like this. Pakistan did not know where the militant leaders were, Sadiq said.
"If we knew, we would take action," he added.