ISLAMABAD, Pakistan - Pakistan may launch a new military offensive in a district near the Afghan border where insurgent leaders are believed to have fled to escape a government onslaught against the Taliban in nearby South Waziristan, the prime minister said yesterday.

The suggestion of another anti-Taliban operation illustrates the intractable challenge facing this nuclear-armed U.S. ally: Even as it squeezes one extremist stronghold in its northwest, insurgents simply regroup in other parts of the rugged, loosely governed region.

Prime Minister Yousuf Raza Gilani said the next front may be Orakzai, a district north of South Waziristan in Pakistan's lawless tribal belt. The government has launched a spate of air strikes there, and the United Nations said Friday that about 40,000 people had already fled.

"The operation in South Waziristan is over. Now there are talks about Orakzai," Gilani told reporters in televised remarks from the eastern city of Lahore.

Gilani later backed down from some of those comments, saying "our military operation in South Waziristan is continuing" and stressing that "there have been lots of successes" in the fight there.

Although Pakistan has had a civilian government for nearly two years after several years of army rule, the military remains a powerful force that is likely to have the last say on where it will send its resources and when it will do so.

The United States has long pushed Pakistan to retake spots along the border that have become safe havens for militants. That pressure is likely to intensify now that 30,000 additional U.S. troops are heading to Afghanistan to take on a resurgent Afghan Taliban.

To Washington's chagrin, Islamabad has focused on groups such as the Pakistani Taliban, which threaten its citizens, rather than militants who attack American and NATO forces across the border. Gilani did not indicate a shift in that strategy yesterday.