ISLAMABAD, Pakistan - Pakistan is objecting to expanded American combat operations in neighboring Afghanistan, creating new fissures in the alliance with Washington at a critical juncture when thousands of new American forces are arriving in the region.

Pakistani Army soldiers in June at a former Taliban base near Khwazakhela in the Swat Valley. (Tyler Hicks/The New York Times) Pakistani officials have told the Obama administration that the Marines fighting the Taliban in southern Afghanistan will force militants across the border into Pakistan, with the potential to further inflame the troubled province of Baluchistan, according to Pakistani intelligence officials.

Pakistan does not have enough troops to deploy to Baluchistan to take on the Taliban without denuding its border with its archenemy, India, the officials said. Dialogue with the Taliban, not more fighting, is in Pakistan's national interest, they said.

The Pakistani account made clear that even as the United States recommits troops and other resources to take on a growing Taliban threat, Pakistani officials still consider India their top priority and the Taliban militants a problem that can be negotiated. In the long term, the Taliban in Afghanistan may even remain potential allies for Pakistan, as they were in the past, once the United States leaves.

The Pakistani officials gave views starkly different from those of American officials regarding the threat presented by top Taliban commanders, some of whom the Americans say have long taken refuge on the Pakistani side of the border.

Recent Pakistani military operations against Taliban in the Swat Valley and parts of the tribal areas have done little to close the gap in perceptions.

Even as Obama administration officials praise the operations, they express frustration that Pakistan is failing to act against the full array of Islamic militants using the country as a base.

Instead, they say, Pakistani authorities have chosen to fight Pakistani Taliban who threaten their government, while ignoring Taliban and other militants fighting Americans in Afghanistan or terrorizing India.

Such tensions have mounted despite a steady rotation of American officials through the region. They were on display last weekend when, during a visit to India, Secretary of State Hillary Rodham Clinton said those who had planned the Sept. 11 attacks were now sheltering in Pakistan. The Pakistani Foreign Ministry issued an immediate rebuttal.

Pakistan's critical assessment was provided as the Obama administration's special envoy for the region, Richard C. Holbrooke, arrived in Pakistan on Tuesday night.

The country's perspective was given in a nearly two-hour briefing on Friday for The New York Times by senior analysts and officials of Pakistan's main spy service, the Directorate for Inter-Services Intelligence. They spoke on the condition of anonymity in keeping with the agency's policy. The main themes of the briefing were echoed in conversations with several military officers over the past few days.

One of the first briefing slides read, in part: "The surge in Afghanistan will further reinforce the perception of a foreign occupation of Afghanistan. It will result in more civilian casualties; further alienate local population. Thus more local resistance to foreign troops."

A major concern is that the American offensive may push Taliban militants over the border into Baluchistan, a province that borders Waziristan in the tribal areas. The Pakistani Army is already fighting a longstanding insurgency of Baluch separatists in the province.

A Taliban spillover would require Pakistan to put more troops there, a Pakistani intelligence official said, troops the country does not have now. Diverting troops from the border with India is out of the question, the official said.

A spokesman for the American and NATO commands in Afghanistan, Rear Adm. Gregory J. Smith, said in an e-mail message on Monday that there was no significant movement of insurgents out of Afghanistan, and no indication of foreign fighters moving into Afghanistan through Baluchistan or Iran, another concern of the Pakistanis.

Pakistani and American officials also cited some positive signs for the alliance. Increased sharing of information has sharpened the accuracy of strikes against militant hide-outs by Pakistani F-16 warplanes and drones operated by the Central Intelligence Agency. And Pakistani and American intelligence operatives are fighting together in dangerous missions to hunt down fighters from the Taliban and Al Qaeda in the tribal areas and in the North-West Frontier Province.

But the intelligence briefing clearly illuminated the differences between the two countries over how, in the American view, Pakistan was still picking proxies and choosing enemies among various Islamic militant groups in Pakistan.

The United States maintains that the Afghan Taliban leader, Mullah Muhammad Omar, leads an inner circle of commanders who guide the war in southern Afghanistan from their base in Quetta, the capital of Baluchistan.

American officials say this Taliban council, known as the Quetta shura, is sheltered by Pakistani authorities, who may yet want to employ the Taliban as future allies in Afghanistan.

In an interview last week, the new leader of American and NATO combat operations in Afghanistan, Gen. Stanley A. McChrystal, paused when asked whether he was getting the cooperation he wanted from Pakistani forces in combating the Quetta shura. "What I would love is for the government of Pakistan to have the ability to completely eliminate the safe havens that the Afghan Taliban enjoy," he said.

The Pakistani intelligence officials denied that Mullah Omar was even in Pakistan, insisting that he was in Afghanistan.

The United States asked Pakistan in recent years to round up 10 Taliban leaders in Quetta, the Pakistani officials said. Of those 10, 6 were killed by the Pakistanis, 2 were probably in Afghanistan, and the remaining 2 presented no threat to the Marines in Afghanistan, the officials said.

They also said no threat was posed by Sirajuddin Haqqani, an Afghan Taliban leader who American military commanders say operates with Pakistani protection out of North Waziristan and equips and trains Taliban fighters for Afghanistan.

Last year, Washington presented evidence to Pakistani leaders that Mr. Haqqani, working with Inter-Services Intelligence, was responsible for the bombing last summer of the Indian Embassy in Kabul that killed 54 people.

Pakistani officials insisted that Mr. Haqqani spent most of his time in Afghanistan, suggesting that the American complaints about him being provided sanctuary were invalid.

Another militant group, Lashkar-e-Taiba, is also a source of deep disagreement.

India and the United States have criticized Pakistan for allowing Hafiz Muhammad Saeed, the founder of Lashkar-e-Taiba, to be freed from jail last month.

The Pakistani officials said Mr. Saeed deserved to be freed because the government had failed to convince the courts that he should be kept in custody. There would be no effort to imprison Mr. Saeed again, in part because he was just an ideologue who did not have an anti-Pakistan agenda, the officials said.