The Taliban have since rejected talks with the government and threatened a wave of revenge attacks for the death of their chief, Hakimullah Mehsud, on November 1. (Agencies)
Khan, a popular opposition politician in the South Asian nation, told Reuters in an interview that the United States had scuppered negotiations at a time when the militants seemed to have become more open to them.
"If there was a chance of peace talks, we should have grabbed it," he said at his sprawling estate outside Islamabad ringed by hills and neatly maintained lawns.
"The Americans basically could have taken out Hakimullah whenever they wanted. I think the timing was to sabotage the peace process.
"The Americans think that if there is fighting going on here ...in our tribal belt, there is less chance of insurgents going over to the other side (Afghanistan) to fight the Americans at a time when they are withdrawing."
Washington has long put pressure on Pakistan to do more to tackle the insurgency but the new government of Prime Minister Nawaz Sharif, elected in May, wants to find a negotiated solution to years of violence.
Attacks against the army and civilians, however, have been on the rise since Sharif came to power, causing concern in a region already nervous about the planned withdrawal of U.S.-led troops from Afghanistan in 2014.
Earlier this week U.S. Secretary of State John Kerry suggested the drone attack was justifiable, while at the time saying Washington was sensitive to Pakistani concerns.
Mehsud had been tentatively open to ceasefire talks with the government, but new Taliban leader Mullah Fazlullah, whose men were behind the attack on schoolgirl Malala Yousafzai last year, strongly opposes negotiations.
The Taliban have since rejected talks with the government and threatened a wave of revenge attacks for the death of their chief, Hakimullah Mehsud, on November 1.