The United States expects Pakistan to launch more military strikes on Islamic militants along its border with Afghanistan even as the Bush administration pumps hundreds of millions of dollars in development aid into lawless tribal regions to fight extremism.

Senior U.S. officials said Tuesday that the administration will back the military efforts of Pakistani President Gen. Pervez Musharraf to quell a resurgence of Al Qaeda and Taliban activity in frontier provinces. But the U.S. will continue aid to the provinces' impoverished residents, the officials said.

"The Pakistani government is dealing decisively with the problems that have been brewing for some time," said Richard Boucher, the assistant secretary of state for south and central Asian affairs, who is expected to travel to Islamabad in early August.

He cited recent developments along the Afghan border, particularly in largely ungoverned Waziristan where Washington says Al Qaeda has regrouped, as well as the military siege on extremists holed up in Islamabad's Red Mosque.

"Now having dealt with the mosque, it's pretty much crossing a line and there's no going back," Boucher said. "I think it shows that the government of Pakistan is prepared to move, to act, against a dangerous militancy that has come to infect various areas and parts of Pakistani society."

As part of that effort, Washington plans to spend $750 million on education, health and economic projects in the tribal areas over the next five years and is hoping to find an additional $300 million to $350 million in the coming year to help revamp Pakistan's beleagured 85,000-member Frontier Corps that patrols the border.

While a civilian "hearts and minds campaign" may offer the best long-term solution to combating extremists in the region, "some elements have to be dealt with militarily," Boucher said.

"We have to remember that some military action is necessary, and will probably have to be taken, that there are elements in these areas that are extremely violent and are out to kill government people, out to kill government leaders, and will not settle for a peaceful way forward," he said.

Boucher's comments came at a news briefing timed to coincide with the release of findings from a new U.S. National Intelligence Estimate that expressed concern about Al Qaeda's resurgence in Pakistan's northwest, which Musharraf's government had allowed to be policed by tribal chiefs.

At the White House, President Bush's homeland security advisor, Fran Townsend, also praised Musharraf's efforts but said the agreement with tribal leaders had been a failure.

His strategy "hasn't worked for Pakistan. It hasn't worked for the United States," she said, stressing, though, that the administration continues to back Musharraf.

"I think it's fair to say President Musharraf is committed to the fact that he will not permit (the tribal areas) to be a safe haven and we will work with him to ensure that that safe haven is denied to them," Townsend said.