The chief political leader in Pakistan’s Khyber Pakhtunkhwa province threatened Thursday to choke off key NATO supply routes if U.S. drone strikes on Pakistan continue, setting up a potential clash within the country’s national government.

Imran Khan, whose Movement for Justice party controls the northwestern province, said he feared that continued drone strikes would undermine efforts by Prime Minister Nawaz Sharif to hold peace talks with the Pakistani Taliban. Sharif said Thursday that dialogue has begun, though Taliban officials stress that the process will quickly unravel if the U.S. drone program is not halted. The latest suspected strike occurred Wednesday night.

“If drone attacks are carried out during peace talks with Taliban, NATO supplies will be stopped,” Khan told reporters at a news conference in the eastern city of Lahore.

It was the second time in less than a week that Khan has suggested that local officials could impede NATO convoys passing through northwestern Pakistan to and from the war in Afghanistan. U.S. and NATO officials had no immediate comment, but Khan’s threat comes as the U.S. military plans to transport hundreds of millions of dollars’ worth of equipment on Pakistani highways ahead of the planned withdrawal of forces by the end of next year.

The supply routes were established when U.S. and NATO forces began pouring into landlocked Afghanistan after the Taliban’s ouster in late 2001, but the routes were closed for seven months between late 2011 and 2012 after a U.S. airstrike on the border of the two countries killed 24 Pakistani soldiers. Pakistan allowed the NATO convoys to restart in July 2012 after Hillary Rodham Clinton, then secretary of state, apologized for the incident.

The U.S. military is moving out the bulk of its equipment from Afghanistan via those routes, the most cost-effective option. The NATO convoys pass through either Khyber Pakhtunkhwa or the southwestern province of Baluchistan on their way to the port city of Karachi.

Both routes have been vulnerable to attacks from militants, and shipments have at times stalled at the border in recent months because of corruption and the Afghan government’s insistence that the United States pay millions of dollars in customs fees. But Pakistan’s government has an agreement with the United States allowing the transports through 2015, and Pakistani security officials help secure the routes.

Although Sharif has also tried in the past to tie the supply routes to the drone issue, he has stressed since taking office in June that he hopes for improved relations with the United States. If Khan’s provincial government follows through on its threat, analysts say, Sharif will have little choice but to step in and exert his constitutional authority to oversee foreign affairs.

“The federal government would be embarrassed and be in
a very unpalatable situation of having to act,” said Khalid Aziz, former chief secretary of Khyber Pakhtunkhwa. “It would lead to a political crisis.”

Tariq Azeem Khan, a former senator and spokesman for the Pakistan Muslim League-Q party, said Imran Khan’s comments showed his “political naivete.”

“Because police come under the local provincial administration, they might try to block them, but without the consensus of the central government, they will not succeed,” he said.

Imran Khan, a former international cricket star, mounted a vigorous campaign in Pakistani parliamentary elections this year by stressing his opposition to the drone strikes and calling for a tougher stance against U.S. policy in the region. His party finished third in the national election but won enough seats in Khyber Pakh­tunkhwa to form a coalition government there.

From that perch, Khan has maintained his profile as a leading champion of peace talks and an end to the U.S. drone strikes. Under pressure from Khan and others domestically, Sharif has also publicly stressed his opposition to the strikes, even though a recent Washington Post report noted that past Pakistani leaders were frequently briefed on the progress of the U.S. drone campaign.

On Thursday, Sharif’s government condemned a suspected U.S. drone strike the night before targeting suspected militants in North Waziristan. No one was killed in the strike, local officials said.

“There is an across-the-board consensus [in Pakistan] that these drone strikes must end,” the Foreign Ministry said in a statement.

After a meeting at the White House last week, Sharif and President Obama issued a joint statement pledging “robust bilateral defense cooperation” in a number of areas, including the movement of NATO cargo through Pakistan.

Shaiq Hussain in Islamabad and Ernesto Londoño in Washington contributed to this report.