The administration also plans "redouble our efforts to look for political approaches" to ending the war, including a recognition that Pakistan "must play an important role" if not a dominant one, in reconciliation talks with the Taliban, he said.

An intelligence estimate prepared for the review concluded that the war in Afghanistan could not be won unless the insurgent sanctuaries were wiped out, and that there was no real indication Pakistan planned to undertake the effort.

But the White House concluded that while Taliban safe havens were "a factor," they were "not the only thing that stands between us and success in Afghanistan," the senior official said.

"We understand the general view a lot of people espouse" in calling for direct U.S. ground attacks, he said of the intelligence estimate. But while the administration's goal is still a Pakistani offensive, the review questioned whether "classic clear, hold and build" operations were the only way to deny the insurgents free access to the borderlands, and asked whether "a range of political, military, counterterrorism and intelligence operations" could achieve the same result.

That view represents a significant shift in administration thinking, perhaps making a virtue of necessity given Pakistani refusal thus far to launch the kind of full-scale ground offensive the United States has sought in North Waziristan.

"The challenge is that when you talk about safe havens in Pakistan, you imagine some traditional military clearing operation that then settles the issue," the official said. While the Pakistani military has cleared insurgents from most of the tribal areas, it remains heavily deployed in those areas, where little building has taken place.

The operations, involving 140,000 Pakistani troops, have pushed concentrations of the Taliban and al-Qaeda into concentrations in North Waziristan, where the United States has launched a withering barrage of missile attacks from remotely piloted drone aircraft, guided in large part by Pakistani intelligence.

Kayani, the Pakistani military chief, has said he will eventually launch an offensive in North Waziristan. But he has told the Americans he cannot spare additional troops from Pakistan's half-million-man army, most of which is deployed along the Indian border, and that he lacks the proper equipment to conduct operations he fears will drive insurgents deeper inside Pakistan's populated areas.

U.S. military commanders have pushed numerous times over the past 18 months for more latitude to allow Special Operations troops to carry out missions across the Pakistan border, officials said. The CIA has similarly sought to expand the territory inside Pakistan it can patrol with armed drones, prodding Pakistan repeatedly for permission to fly drones over Quetta, a city in Baluchistan where the Taliban's political leaders are thought to be based.

The senior administration official, who called the proposals "ideas, not even operational concepts much less plans," said they have were rejected by the White House in the most recent review, as they have repeatedly been in the past, as likely to cause more harm than good.

"We've got to increasingly try to look at this through their lens," the official said of Pakistan, "not because we accept it wholesale, but because their actions are going to continue to be driven by their perspective."

"In the long run," he said, "our objectives have to do with the defeat of al-Qaeda and the security of Pakistan's nuclear weapons. If you're not careful here . . .you may do something in the short run that makes gains against the policy objective in North Waziristan, but proves self-defeating in the long term."