(CNN) -- The Pakistan Taliban have voted to elect Asmatullah Shaheen, who is on Pakistan's most wanted list, as their interim head, according to an official for the group. The move comes after former chief Hakimullah Mehsud was killed in a U.S. drone strike on Friday.
The group, also known as Tehreek-e-Taliban Pakistan, will not be making an announcement on a new permanent leader for several more days, according to Azam Tariq, a member of the Pakistan Taliban's Shura Council, their centralized decision-making body..
Meanwhile, the U.S. ambassador to Islamabad was summoned to Pakistan's Foreign Ministry on Saturday.
Foreign Ministry spokesman Aizaz Ahmed Chaudhry did not explain why the envoy was summoned. A U.S. State Department official confirmed the meeting to CNN but would not disclose details about it.
The State Department official would not discuss U.S. operations in Pakistan but pointed to the Pakistan Taliban's 2009 attack on a U.S. base in Afghanistan and claims of responsibility for a failed attempt to bomb Times Square in New York.
The official was not authorized to speak publicly and is not being named by CNN.
Pakistan: Peace talks will go ahead
Pakistani Information Minister Pervez Rasheed insisted that Mehsud's death would not delay proposed peace talks between the government and the Pakistan Taliban, amid concern that anger about the strike might derail the process.
Rasheed condemned the use of drones in Pakistan. "Drones are used for killing, but they will not let the peace process be killed with it," the minister told reporters.
Mehsud, who had a $5 million U.S. bounty on his head for his alleged involvement in the 2009 attack, was killed in a drone strike in northwestern Pakistan, senior U.S. and Pakistani officials told CNN.
He was buried overnight, though the body was burned beyond recognition, Taliban sources said.
The Afghan Taliban condemned the drone strike as "cowardly" and "barbaric" in a statement posted on their website Saturday, the SITE intelligence group said. The statement urged the Pakistani government and people to take measures to stop the attacks.
Pakistan braces for reprisals
There are fears the killing of Mehsud may spark a surge in violence.
This is in part because the attack in Afghanistan in 2009 -- in which seven U.S. citizens died -- was launched in response to a strike that killed another Taliban leader, Baitullah Mehsud, four months earlier.
The Haqqani Network, designated by the United States as a terrorist organization, vowed to avenge Hakimullah Mehsud's death. Spokesman Ahmed Yousaf said the group will launch attacks within a few days.
The network is blamed for more than 1,000 U.S. casualties in Afghanistan.
Security around Peshawar, the capital city of Khyber Pakhtunkhwa province in northwest Pakistan, is being beefed up as police and security brace for reprisal attacks, Home Secretary Akhtar Ali Shah said.
"Since this drone strike, we are waiting for a reaction," he said. "We know the reaction will be strong. We have strengthened security in Peshawar, especially at the entry points into the city. We have extra security on patrol with sniffer dogs."
Strike hit Taliban stronghold
Three other people were killed in Friday's strike, Pakistani intelligence sources and tribal officials said.
They described the incident as a suspected U.S. drone strike in a remote area of Pakistan's North Waziristan region, a Taliban stronghold bordering Afghanistan and Khyber Pakhtunkhwa province.
One missile hit a compound and another struck a car nearby, the Pakistani sources said.
This is not the first time Hakimullah Mehsud -- who took the reins of the Pakistan Taliban in 2009 -- has been reported killed after a drone strike. In February 2010, multiple sources said he had died after being hit in a drone strike in Pakistan a month earlier.
But reports that he was alive surfaced in April of that year, and in May 2010 he appeared in a video in which he vowed attacks on major U.S. cities.
The fact that senior Pakistani government officials have commented so quickly on the news of his death this time adds credence to the reports.
Pakistan Taliban claimed Times Square plot
The Pakistan Taliban, who have long been conducting an insurgency against the Pakistani government, claimed responsibility for the December 2009 suicide bombing at the United States' Forward Operating Base Chapman in Khost, Afghanistan. Five CIA officers were among the seven U.S. citizens killed, and a member of Jordanian intelligence also died.
The U.S. Justice Department charged Hakimullah Mehsud in the summer of 2010 for his alleged involvement in the attack, and U.S. officials offered a $5 million reward for information leading to his capture.
The group also claimed responsibility for a failed May 2010 attempt to detonate a car bomb in New York's Times Square. The following September, the U.S. State Department designated the Pakistan Taliban a foreign terrorist organization.
Mehsud took over from Baitullah Mehsud, a fellow clan member, in 2009 after the latter was killed in a U.S. drone strike.
Hakimullah Mehsud's death could make progress in proposed peace talks between the Pakistani government and Pakistan Taliban more difficult.
A relatively young and charismatic leader, he held together a disparate group with different tribal and other allegiances.
There had reportedly been talks about him being involved in peace talks with Pakistan's government.
His killing may upset some elements within the Pakistan Taliban if they believe that the Pakistani government was involved.
The Pakistan Taliban could also pose an increased security threat if they splinter into smaller groups, which could be harder for security forces to detect.
There has been a series of suicide bombings in the region over the past couple of years.
CNN's Shaista Aziz, David Simpson and Susanna Capelouto contributed to this report.