Pakistani Taliban chief Hakimullah Mehsud (C) sits with other militants in South Waziristan, in this file still image taken from video shot October 4, 2009 and released October 5, 2009. A US drone strike in Pakistan killed Hakimullah Mehsud, the head of the Pakistani Taliban, on November 1, 2013. [Photo/Agencies]

ISLAMABAD — The Pakistani government Saturday accused the US of sabotaging peace talks with domestic Taliban fighters by killing their leader in a drone strike, as the militants began the process of choosing a successor.

The rise in tension, even though the US took out Pakistan's No. 1 enemy, shows just how complicated the relationship between the professed allies can be. The two repeatedly have clashed over issues such as drone strikes and Pakistan's alleged support for militants fighting US troops in neighboring Afghanistan.

The Pakistani Taliban leader slain Friday, Hakimullah Mehsud, was a ruthless figure known for a deadly attack on a CIA base in Afghanistan and a bloody campaign that killed thousands of Pakistani civilians and security personnel.

The Pakistani army has launched numerous operations in the country's northwest in a failed attempt to subdue the group, which aims to topple Pakistan's democratic system and impose a harsh version of Islamic law. It also seeks an end to the country's unpopular alliance with the US

Pakistan's government, which took office in June, has pushed peace talks with the Taliban as the best way to end the conflict, although many people are skeptical a deal is possible.

The drone strike that killed Mehsud in the North Waziristan tribal area came a day before the government was to send a three-member delegation of clerics to the region with a formal invitation to start peace talks, Interior Minister Chaudhry Nisar Ali Khan said. It never ended up going.

Khan called the drone attack "murder" to the peace effort, but hoped the process could continue. He said he warned the US ambassador previously that American drone strikes should not be carried out while Pakistan was trying to hold peace talks and no Taliban leader should be targeted. The government later summoned the US ambassador to complain.

When asked whether he thought the US was trying to deliberately scuttle the peace process, the minister responded: "Absolutely."

"The efforts have been ambushed," the minister said.

He did not say what he felt the US stood to gain but questioned: "Why do they want us to be insecure?"

Another prominent political leader, Imran Khan, whose party controls the government in northwest Khyber Pakhtunkhwa province, threatened to block trucks carrying supplies to NATO troops in Afghanistan over the strike. He said he would push the provincial assembly to adopt a resolution to block the supplies and would do the same nationally.

"Dialogue has been broken with this drone attack," Imran Khan said.

The interior minister said as soon as Pakistani Prime Minister Nawaz Sharif returns from abroad, a national security meeting will be convened to discuss US-Pakistan relations and cooperation. He would not specifically address the threatened supply lines closure.

Azam Tariq, the Pakistani Taliban spokesman in the South Waziristan tribal area, provided the first official confirmation of Mehsud's death Saturday.

"We are proud of the martyrdom of Hakimullah Mehsud," Tariq told The Associated Press by telephone. "We will continue our activities."

Mehsud and the other four militants killed in the strike were buried Saturday at an undisclosed location, Taliban commanders said. Drones still flew over the area, and witnesses in the towns of Mir Ali and Miran Shah reported that Mehsud's supporters fired at them in anger.

The Taliban's Shura Council, a group of commanders representing the group's various wings, met Saturday to choose Mehsud's successor, Tariq said. The Shura will meet for a few days before making a decision.

The two main candidates to succeed Mehsud are Khan Sayed, the Pakistani Taliban leader in the South Waziristan tribal area, and Mullah Fazlullah, the chief in the northwest Swat Valley, Pakistani intelligence officials and Taliban commanders said.

Omar Khalid Khurasani, who heads the group's wing in the Mohmand tribal area, is also in the running, militant commanders said. He was not believed to be a strong candidate.

Several Taliban commanders reported that a majority of Shura members voted for Sayed, but they were still waiting for commanders from remote areas to arrive. One commander said the Shura chose a caretaker chief, Sheharyar Mehsud, to lead until the group chooses a permanent successor.

All officials and the commanders spoke on condition of anonymity because they were not authorized to talk to journalists.

A leadership struggle broke out after Hakimullah Mehsud's predecessor, Baitullah Mehsud, was killed in a drone strike in 2009. It took the group weeks to choose a new leader. It's unclear if there will be a similar leadership struggle.

Bruce Riedel, a former CIA officer and adviser to the Obama administration who helped craft the agency's drone campaign, said Hakimullah Mehsud's death was "a serious blow to the Pakistani Taliban which may spark internal fractures in the movement."

Afghan Taliban spokesman Zabiullah Mujahid mourned Mehsud's death in a statement and criticized the "cowardly American attack" that killed him. The Afghan and Pakistani Taliban are allies but have mostly focused their attacks on opposite sides of the border.

Mehsud gained a reputation as a merciless planner of suicide attacks in Pakistan. After taking over as the Pakistani Taliban's leader, he tried to internationalize the group's focus. He's believed to have been behind a failed car bombing in New York's Times Square in 2010 and was on the US most-wanted terrorist lists with a $5 million bounty.

Mehsud's death will complicate efforts by the government to negotiate a peace deal. After a drone strike killed the group's No. 2 in May, the Pakistani Taliban fiercely rejected any idea of peace talks and accused the government of cooperating with the US

In recent weeks, the Pakistani Taliban appeared to soften its position against talks but had still made multiple demands for preconditions to any negotiating, including the end of drone strikes in the tribal areas.

Pakistani officials regularly criticize the attacks as a violation of the country's sovereignty, but the government is known to have supported some strikes in the past.

"We have properly understood the duel policy of the Pakistani government and its hypocrisy," the Pakistani Taliban spokesman said Saturday.