ISLAMABAD - The United States has renewed pressure on Pakistan to expand the areas where CIA drones can operate inside the country, reflecting concern that the U.S. war effort in Afghanistan is being undermined by insurgents' continued ability to take sanctuary across the border, U.S. and Pakistani officials said.

The U.S. appeal has focused on the area surrounding the Pakistani city of Quetta, where the Afghan Taliban leadership is thought to be based. But the request also seeks to expand the boundaries for drone strikes in the tribal areas, which have been targeted in 101 attacks this year, the officials said.

Pakistan has rejected the request, officials said. Instead, the country has agreed to more modest measures, including an expanded CIA presence in Quetta, where the agency and Pakistan's Inter-Services Intelligence (ISI) directorate have established teams seeking to locate and capture senior members of the Taliban.

The disagreement over the scope of the drone program underscores broader tensions between the United States and Pakistan, wary allies that are increasingly pointing fingers at one another over the rising levels of insurgent violence on both sides of the Afghan-Pakistan border.

Senior Pakistani officials expressed resentment over what they described as misplaced U.S. pressure to do more, saying the United States has not controlled the Afghan side of the border, is preoccupied by arbitrary military deadlines and has little regard for Pakistan's internal security problems.

"You expect us to open the skies for anything that you can fly," said a high-ranking Pakistani intelligence official, who described the Quetta request as an affront to Pakistani sovereignty. "In which country can you do that?"

U.S. officials confirmed the request for expanded drone flights. They cited concern that Quetta functions not only as a sanctuary for Taliban leaders but also as a base for sending money, recruits and explosives to Taliban forces inside Afghanistan.

"If they understand our side, they know the patience is running out," a senior NATO military official said.

The CIA's drone campaign in Pakistan has accelerated dramatically in recent months, with 47 attacks recorded since the beginning of September, according to The Long War Journal, a Web site that tracks the strikes. By contrast, there were 45 strikes in the first five years of the drone program.

But Pakistan places strict boundaries on where CIA drones can fly. The unmanned aircraft may patrol designated flight "boxes" over the country's tribal belt but not other provinces, including Baluchistan, which encompasses Quetta.

"They want to increase the size of the boxes, they want to relocate the boxes," a second Pakistani intelligence official said of the latest U.S. requests. "I don't think we are going to go any further."

He and others spoke on condition of anonymity, citing the clandestine nature of a program that neither government will publicly acknowledge.