The White House must consider its ally Pakistan President Pervez Musharraf [Images] as "gone", a former top United States security official said after the military ruler imposed emergency in his country.

"I will be very surprised if he (Musharraf) lasts even six months," Xenia Dormandy, who until last year was the Director for South Asia at the National Security Council, told the Washington Post.

Dormandy, who feels Musharraf will be chucked out by the people or by his own military, faulted the Bush administration for sending "mixed messages" to the general in recent months, allowing him to believe he could weather the fallout from a declaration of emergency powers.

Stephen Cohen of the Brooking Institution and a noted expert on Pakistan, said the US had made a mistake by placing "all of our chips on Musharraf".

"The train is derailed and off the tracks. We have to give ourselves a share of the responsibility for this. I don't think there is anything we can do. We are not big players in this anymore," he said.

Chairman of the Senate Foreign Relations Committee Joseph Biden, a tough critic of the Bush administration's Pakistan policy, called for a "move from a Musharraf policy to a Pakistan policy".

Biden said the US had to built "a new relationship with the Pakistani people, with more non-military aid, sustained over a long period of time, so that the moderate majority in Pakistan has a chance to succeed".