The head of U.S. Central Command said Sunday that Al Qaeda is no longer operating in Afghanistan, with its senior leadership having moved to the western region of Pakistan. 

Gen. David Petraeus said affiliated groups have "enclaves and sanctuaries" in Afghanistan and that "tentacles of Al Qaeda" have touched countries throughout the Middle East and northern Africa. But he said the terrorist group has suffered" very significant losses" in recent months, and agreed with Afghan President Hamid Karzai's recent assessment that there is no Al Qaeda based in his country. 

Still, he said he believes Usama bin Laden and his No. 2 Ayman al-Zawahiri remain in charge of the terrorist network. 

"They surface periodically. We see communications that they send out," Petraeus said. 

Though Petraeus said nobody can provide an accurate location for either terrorist, he said Al Qaeda senior leadership clearly is now rooted in the border region of western Pakistan. 

"There's no question that Al Qaeda's senior leadership has been there and has been in operation for years," Petraeus said. 

The head of U.S. Central Command, speaking on "FOX News Sunday," warned of the severe threat extremist groups now pose to Pakistan but praised the U.S. ally for what he described as a coordinated campaign to beat back an uprising of Taliban forces. 

He said that the Taliban's effort to extend their territory beyond the northern Swat valley seems to have "galvanized all of Pakistan" against the group. 

"There is a degree of unanimity that there must be swift and effective action taken against the Taliban in Pakistan," Petraeus said, warning of the dire consequences of a Pakistan defeat. 

"This is not a U.S. fight that Pakistan is carrying out at this point ... This is a Pakistani fight, a Pakistani battle, with elements that as we've mentioned threaten the very existence of the Pakistani state." 

Petraeus spoke Sunday on "FOX News Sunday" and CNN's "State of the Union." 

The Associated Press contributed to this report.