The US envoy said it was unclear if the military had defeated the Taliban in the region or simply driven them underground.
Pakistan has declared its three-month anti-Taliban offensive in the Swat Valley a success, claiming to have killed more than 1,800 militants. But on Wednesday US special representative for Pakistan and Afghanistan Richard Holbrooke cast doubt on whether the push had actually achieved its goal: defeating the Taliban.
Pakistan launched the offensive in late April, after the Taliban flouted a peace deal signed in February and took control of the area, setting off alarm bells in Washington. Mr. Holbrooke's remarks were a rare expression of doubt over Swat by a member of the Obama administration, which has praised Pakistan's effort. They indicate a growing sense of worry that rather than crushing the Taliban, the offensive may have simple pushed the fighters underground.
"We don't know exactly to what extent the Pakistani Army dispersed or destroyed the enemy," Holbrooke told reporters on Wednesday, after returning from Pakistan and Afghanistan, according to Reuters. "The test of this operation is, of course, when the refugees return. Can they go home? Are they safe? And we're just going to have to wait and see."