The threat of war with India may lead Pakistan to reallocate troops, a move that could affect the pursuit of Al Qaeda and Taliban fighters along the border with Afghanistan and the U.N. peacekeeping mission in Sierra Leone, a senior defense official said Thursday.

"This is one of the many options," the official, speaking on condition of anonymity, told The Associated Press. He said Pakistan is also considering recalling 500,000 reservists in order "to face any situation in the event of a war with India."

The announcement came a day after fellow nuclear power India warned Pakistan that it is not bluffing about a "decisive battle" against terrorism. Cross-border shelling in the disputed Kashmir region in the last week has killed dozens and reignited fears of another war in the region.

Washington has expressed concerns about any reduction of Pakistani forces deployed near the Afghan frontier. Those forces have arrested hundreds of Taliban and Al Qaeda fighters, including Usama bin Laden's top lieutenant, Abu Zubaydah, who is now in U.S. custody.

"Pakistani troops deployed along the western borders to prevent remnants of Taliban and Al Qaeda from sneaking into Pakistan can also be redeployed where they are needed if the tension with India does not ease in the days to come," the defense official said, emphasizing that no final decision has been made.

A Pakistani pullout from Sierra Leone would have serious repercussions for efforts to foster stability in the West African nation. The 14,500 troops there comprise the world's largest international peacekeeping force, and Pakistan's 4,320-strong force is the largest contingent.

Along with British troops and the army of neighboring Guinea, the U.N. force helped crush a notorious rebel movement that killed tens of thousands of civilians during a 10-year campaign to control the government and diamond mines.

The Revolutionary United Front rebels signed a cease-fire in late 2000 and turned in their guns the following year under a U.N. disarmament program. The war was officially declared over in January and elections were held last week. Government forces have now deployed across the country, but security in many areas is still largely in the hands of U.N. troops.

Pakistan is a chief supporter of the U.S.-led war on terrorism. Coalition forces are still using the country's air bases and other facilities to pursue those it says are responsible for the Sept. 11 attacks on the United States.

"The withdrawal of Pakistani troops-- if made at some stage-- will not affect our relations with the U.S.-led coalition in war against terrorism," the official said. "We will continue support to the international community in the war against terrorism."