Pakistani military officials say that while security has improved in the Swat Valley, it will take more time to completely expel the Taliban from the region.
The military's chief spokesman, Major General Athar Abbas, said Wednesday that it may take two more months of fighting to secure the area.
An army commander Major General Ijaz Awan said the military may also have to remain in the region for at least a year to maintain security.
Pakistani forces retook control of Swat Valley's main town of Mingora last week. Awan says from a military standpoint, displaced civilians could start returning to Mingora, but says it will take weeks to restore the town's electricity and water supplies.
Meantime, U.S. special envoy Richard Holbrooke arrived in Pakistan Wednesday to meet with President Asif Ali Zardari and to assess the refugee situation.
The State Department said Holbrooke will meet displaced Pakistanis and relief organizations during his three-day trip.
Fighting between government troops and Taliban militants has displaced an estimated 2.5 million people from the Swat Valley and adjoining areas in recent weeks.
Also Wednesday, Pakistani school officials said Taliban militants in the northwest are still holding more than 40 students captive, despite earlier claims of their rescue.
Military and government officials previously said troops had rescued all of the students and staff who were kidnapped Monday. The officials gave their numbers as 71 students and nine staff members.
Militants reportedly intercepted a convoy of students and staff from Razmak Cadet College as it was traveling from North Waziristan to Bannu district.
Some information for this report was provided by AFP, AP and Reuters.