Click here for the latest news analysis on drones.
About 10,000 people participated in Saturday's protest. The protesters included members of Khan's party and two others that are coalition partners in the Khyber Pakhtunkhwa government. They shouted anti-U.S. slogans such as "Down with America" and "Stop drone attacks."
"I am participating in today's sit-in to convey a message to America that we hate them, since they are killing our people in drone attacks," university student Hussain Shah said. "America must stop drone attacks for peace in our country."
The federal information minister, Pervez Rashid, said the national government's anti-drone stance was clear and accused Khan of "playing politics" on the issue.
Drone strikes are widely unpopular with Pakistan's public because they are seen as violating the nation's sovereignty and because they are believed to kill many innocent civilians. Human-rights organizations have said hundreds of civilians have died in the attacks, although the U.S. insists the number is much lower.
The land routes through Pakistan from the southern port city of Karachi to Torkham and another border crossing in southwest Baluchistan province have been key to getting supplies to NATO troops in Afghanistan. They now are increasingly being used to ship equipment out of Afghanistan as the U.S. seeks to withdraw most of its combat troops from the country by the end of 2014.
The routes have been closed before. Islamabad blocked the routes for seven months after U.S. airstrikes mistakenly killed two dozen soldiers on the Afghan border in November 2011. Pakistan finally reopened the routes after the U.S. apologized.