Later in the day, one of Khan's allies, the right wing Jamaat-e-Islami party, led thousands in a protest against drone attacks and the NATO supply line in the southern port city of Karachi, where the shipments originate.
Khan, whose Tehreek-e-Insaf party controls the Khyber Pakhtunkhwa provincial government, has been a vocal critic of drone attacks. He and other officials say the strikes are a violation of the country's sovereignty, although the federal government is known to have secretly supported some of the attacks in the past.
Khan led thousands of supporters in a protest near Peshawar on Saturday in which they blocked a road that led to one of two border crossings used by trucks carrying NATO supplies in and out of Afghanistan. The other crossing is in southwest Baluchistan province. The demonstration had more symbolic value than practical impact because there is normally very little NATO supply traffic on the weekend.
Federal Information Minister Pervez Rashid accused Khan on Sunday of trying to damage Pakistan's relationship with NATO countries and neighboring Afghanistan.
"Anyone who wants to disturb our relations with neighbors is not serving the country," Rashid said. "Because of Imran Khan we could be isolated in the world."
Rashid said on Saturday that the federal government's anti-drone stance was clear and accused Khan of "playing politics" with the issue.
Pakistani Prime Minister Nawaz Sharif has also been a vocal critic of drone strikes since he took office in June. He pushed President Barack Obama to end the attacks during a visit to Washington in October, but the U.S. has shown no indication it will stop using a tool it views as vital for battling al-Qaida and the Taliban.
Khan has pushed the federal government to block NATO supplies across the country to force the U.S. to end drone strikes, but it has shown little interest in doing so. While Sharif has said he wants the attacks to end, he has also made clear that he values a friendly relationship with the U.S. It's unclear if the government will take action to prevent Khan's supporters from stopping NATO supply trucks.
The land routes through Pakistan have been key to getting supplies to NATO troops in Afghanistan. They now increasingly are 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 in the past. The Pakistani government blocked the routes for seven months following U.S. airstrikes that accidentally killed two dozen soldiers on the Afghan border in November 2011. Pakistan finally reopened the routes after the U.S. apologized.
Also Sunday, a roadside bomb killed two Pakistanis soldiers and wounded five others in the North Waziristan tribal area, said military officials, speaking on condition of anonymity in line with military policy. They accused the Pakistani Taliban of planting the bomb.
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Associated Press writers Zarar Khan and Sebastian Abbot in Islamabad and Adil Jawad in Karachi contributed to this report.