Military commanders in Afghanistan are urging Bush Administration officials to allow them to attack Pakistani extremists in the tribal areas on the Afghan border.

The requests have been rebuffed for now, the officials said, after deliberations in Washington among senior Bush administration officials who fear that attacking Pakistani radicals may anger Pakistan’s new government, which is negotiating with the militants, and destabilize an already fragile security situation.

American commanders would prefer that Pakistani forces attack the militants, but Pakistani military operations in the tribal areas have slowed recently to avoid upsetting the negotiations. Pakistan’s government has given the Central Intelligence Agency limited authority to kill Arab and other foreign operatives in the tribal areas, using remotely piloted Predator aircraft.

But administration officials say the Pakistani government has put far greater restrictions on American operations against indigenous Pakistani militant groups, including one thought to have been behind the assassination of former Prime Minister Benazir Bhutto. American intelligence officials say that the threat emanating from Pakistan’s tribal areas is growing, and that Pakistani networks there have taken on an increasingly important role as an ally of Al Qaeda in plotting attacks against American and other allied troops in Afghanistan, and in helping foreign operatives plan attacks on targets in the West.

The officials said the American military’s proposals included options for limited cross-border artillery strikes into Pakistan, missile attacks by Predator aircraft or raids by small teams of C.I.A. paramilitary forces or Special Operations forces.