Mr. Gilani and Mr. Brown held talks here Thursday, two days after President Obama announced plans to send 30,000 extra American troops to Afghanistan — a move that rattled nerves across a region spanning the long, mountainous and porous border between Afghanistan and Pakistan.

In particular, Washington’s assertion that American troops could begin leaving in 18 months provoked anxiety in Afghanistan and rekindled longstanding fears in Pakistan that America would abruptly withdraw, leaving Pakistan to fend for itself. Both countries face intertwined Taliban insurgencies.

“Regarding the new policy of President Obama, we are studying that policy,” Mr. Gilani said. “We need more clarity on it, and when we get more clarity on it we can see what we can implement on that plan.”