Their main concern is that because President Pervez Musharraf is no longer calling the shots in Pakistan and the Bush administration has "limited leverage" with Pakistan's new government.
Moreover, the new leaders manning Pakistan's affairs - PPP Co-Chairman Asif Ali Zardari and PML-N leader Nawaz Sharif, have vowed to honour their poll campaign pledges to break with Musharraf's emphasis on using military force in the tribal areas.
The new regime in Islamabad believes that the current peace talks have a better chance for lasting success than those by Musharraf's government because now instead of military leaders civilian Pashtun officials were negotiating directly with tribal elders.
Fearing that the peace accord might lead to further unraveling of security in the region, they are of the view that hard-core Qaeda fighters numbering between 150 and 500 are operating in the tribal areas, reported the New York Times.
Cross-border attacks into Afghanistan by militants based in Pakistan doubled in March from the same period a year ago and have not diminished in April, while Pakistani counterinsurgency operations in the tribal areas have dropped sharply during the talks, said a Western military official.
"I have no information to suggest that what Pakistanis have done in past two to three months has seriously impeded Al Qaeda's ability" to recruit new members and train them in small compounds in the tribal areas, the paper quoted a senior US intelligence official as saying.
Counter-terrorism officials in the US administration express concern that the new coalition government in Islamabad may withdraw some of the 120,000 Pakistani troops in the border area or curtail flights by the Central Intelligence Agency's armed Predator aircraft in the region.
The problems confronting the administration reflect what critics say is a failure over the past several years to pay sufficient attention to the growing numbers of Qaeda and Taliban fighters drawn to safe havens in the tribal area. Even under Musharraf, the US failed to develop a government-wide plan to combat the militancy in the turbulent borderlands, these critics say.