(CNN) -- A U.S. drone strike that killed the Pakistan Taliban's leader last week won't derail government efforts at peace talks with the group, Pakistan's prime minister said Monday.
"A drone strike under these circumstances has harmed the dialogue and peace efforts of the government," Prime Minister Nawaz Sharif's office said in a statement. "But we believe that we will not ... allow the dialogue and peace efforts to get derailed."
At a Cabinet meeting Monday, ministers decried drone attacks as "unacceptable" and called them a violation of Pakistan's sovereignty.
"Diplomatic efforts will be continued to stop these attacks," the statement said. "Given Pakistani peoples' resolve and sacrifices in this war against terrorism, it is incumbent upon the international community to support this endeavor of the government for the accomplishment of peace. The government of Pakistan will not allow any internal or external force to sabotage the dialogue process."
The meeting came three days after a U.S. drone strike killed Pakistan Taliban leader Hakimullah Mehsud.
Mehsud, who had a $5 million U.S. bounty on his head for his alleged involvement in the 2009 attack on a U.S. base in Afghanistan, was killed in northwestern Pakistan Friday, senior U.S. and Pakistani officials told CNN.
On Monday, Pakistani jihadists distributed a photograph purporting to show Mehsud before his burial and describing him as a martyr, the SITE Intelligence Group said.
New leader elected
An official with the Pakistan Taliban said Sunday that the group had voted to elect Asmatullah Shaheen, who is on Pakistan's most-wanted list, as its interim head.
The group, also known as Tehrik-e-Taliban Pakistan, will not be making an announcement on a new permanent leader for several days, according to Azam Tariq, a member of the Pakistan Taliban's Shura Council.
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 but would not disclose details about it.
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, along with a member of Jordanian intelligence.
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 as a foreign terrorist organization.
Pakistan has stepped up security, and officials have said they're bracing for reprisals after Friday's drone strike.
Prospects for peace
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.
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.
CNN's Shaista Aziz, David Simpson and Susanna Capelouto contributed to this report.