A U.S. drone strike killed the chief of the Pakistani Taliban on Friday, local intelligence officials said, in an attack that could cripple the group but undermine an effort by Pakistan’s government to engage militants in peace talks.

If verified, the death of Hakimullah Mehsud would be a victory for U.S. officials who have spent years hunting down a leader implicated in a 2009 attack that killed seven Americans at a CIA outpost in eastern Afghanistan.

But the drone strike also threatened to add to strains between the United States and Pakistan, whose new prime minister, Nawaz Sharif, had announced earlier in the day that his government would begin talks aimed at reaching a negotiated settlement with the group.

With that plan called off after the strike, Pakistani Interior Minister Chaudhry Nisar Ali Khan issued a statement accusing the United States of carrying out “a conspiracy to sabotage the peace talks.’’

On Saturday, Pakistan filed a formal protest with the U.S. ambassador and plans to protest to all five permanent members of the U.N. Security Council, as well, according to the Foreign Ministry. Khan said that the government intends to review the “entire perspective of the U.S.-Pakistan relationship” at the highest levels.

Truman Project Defense Council Member Pierre Hines talks with Nia-Malika Henderson three driving factors behind the boom in drone usage over the past 10 years. (The Washington Post)

“Our efforts have been ambushed, and it was not an ambush from the front,” he said.

Intelligence officials in northwestern Pakistan said Friday that Mehsud had been killed after he met with other senior Taliban leaders to discuss the peace initiative, one aimed at ending years of violence that has claimed more than 45,000 lives. A local Taliban commander confirmed Mehsud’s death.

In Washington, National Security Council spokeswoman Caitlin Hayden said U.S. officials are not in a position to confirm reports of Mehsud’s death, “but if true, this would be a serious loss” for the Pakistani Taliban.

The attack came just eight days after a White House meeting in which Sharif and President Obama pledged closer cooperation between the two countries. In Pakistan, those who expressed outrage over the strike included Imran Khan, a senior political leader who said he would immediately press to have the government cut off NATO supply routes through northwest Pakistan, the Dawn newspaper reported.

Khan was following through on a threat he made Thursday, when he warned that U.S. supply routes to and from Afghanistan would be disrupted if the drone strikes were to continue. Other Pakistani and Taliban officials said it could take a few days to fully assess the political and strategic impact of the strike.

The interior minister said Saturday that the government will decide after Sharif returns to Islamabad whether to suspend the convoys.

Mehsud, who is believed to be about 33, took over as head of the Pakistani Taliban in 2009 after the group’s leader, Baitullah Mehsud, was killed in a U.S. drone strike. The United States had offered a $5 million bounty for his capture.

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Hakimullah Mehsud has been viewed as the linchpin for a broad range of Islamist militant groups that have sought to impose strict Islamic law in Pakistan. According to a 2010 BBC profile, Mehsud started out organizing attacks on NATO convoys in northwest Pakistan during the early years of the war in Afghanistan. By 2009, he was the group’s commander and appeared in a video alongside the Jordanian man who carried out the suicide bombing at the CIA facility in Afghanistan.

In May 2010, Mehsud also surfaced in videos in which he vowed to attack U.S. cities. Hayden of the National Security Council noted that the Pakistani Taliban claimed responsibility for the failed bombing in New York’s Times Square on May 1, 2010. Later that year, the U.S. government designated the Pakistani Taliban a terrorist group and formally charged Mehsud in the attack on the CIA base.

In recent months, Mehsud had kept a low profile, fearful of the U.S. drone campaign, Taliban officials said. He had relied on one of his top lieutenants, Latif Mehsud, to shuttle messages for him. But U.S. forces arrested Latif Mehsud as he traveled in Afghanistan several weeks ago.

Rifaat S. Hussain, a noted military analyst in Islamabad, said Hakimullah Mehsud’s death would be a major setback for the militant group. “The larger strategic implication of getting him — along with his deputy in U.S. custody — is that it puts them out of action,” Hussain said. “They are now faced with a scenario where, if they pull out of the negotiations, these drone strikes will continue to haunt them.”

Even before Friday’s strike, there were signs that the Pakistani Taliban’s leadership was splintering because of tactical and ideological differences. In the wake of Mehsud’s death, analysts said, the group’s cohesion could further break down, hindering Sharif’s effort to negotiate a peace deal with any one faction.

According to three local intelligence officials, Mehsud, his driver, his uncle and two guards were killed in Friday’s strike, which the officials said occurred outside a small mosque where several senior Taliban leaders had been meeting.

“They left the mosque for a [Taliban] compound, and when the vehicle was parked, a drone fired three missiles and hit the vehicle,” one official said, relaying information he had received from a local informer.

Reached by phone, a local Taliban commander in North Waziristan confirmed that Mehsud had been killed. The “respected chief has been martyred in the drone attack on Friday,” said the commander, who spoke on the condition of anonymity.

Until Friday, the most recent major blow to the Pakistani Taliban had come in May, when the group’s second-ranking leader, Wali ur-Rehman, was killed in a drone strike. A month later, the Pakistani Taliban asserted responsibility for killing 10 foreign mountain climbers, including an American, who were trying to scale Pakistan’s second-highest mountain.

The group said that attack was in retaliation for Rehman’s death.

Hussain, the analyst in Pakistan, said U.S. officials probably calculated that the fallout from the strike would subside quickly, despite the potential for backlash from Pakistani officials.

“If they can decapitate the top military leadership of the [Taliban], this can create a case where the U.S. government can actually one day cease the drone attacks, and thereby limit the damage to public opinion” for the United States in Pakistan, Hussain said.

Haq Nawaz Khan and Shaiq Hussain in Islamabad and Greg Miller in Washington contributed to this report.