LONDON — American drones on Friday killed the leader of the Pakistani Taliban, dealing a major blow to a militant group that has terrorized Pakistan and that tried to set off a car bomb in New York City in 2010, according to Pakistani intelligence officials and militant commanders in the tribal belt.

The death of the leader, Hakimullah Mehsud, is a signal achievement for the covert C.I.A. program at a time when drones themselves have come under criticism from human rights groups and other critics in Pakistan and the United States over the issue of civilian casualties.

While prior reports of Mr. Mehsud’s death have proved false — ultimately serving only to burnish his credentials as an untouchable renegade — within hours there was a strong sense from multiple sources, including two American defense officials, that this time he had not escaped.

“Hakimullah has been martyred,” said a local Taliban commander, speaking by phone from the tribal belt on the condition of anonymity. Pakistani officials backed up that assessment.