The Afghan Taliban confirmed on Wednesday that their leader Mullah Akhtar Mansour was killed in a US drone strike last week and that they have appointed a successor — a scholar known for extremist views who is unlikely to back a peace process with Kabul. In a statement sent to the media, the Taliban said their new leader is Mullah Haibatullah Akhundzada, one of Mansour's two deputies. The insurgent group said he was chosen at a meeting of Taliban leaders, which is believed to have taken place in Pakistan, but offered no other details. Meanwhile, Pakistan's military says the country's army chief met with US Ambassador David Hale to express Islamabad's serious concerns over the drone strike that killed the former Taliban leader. Wednesday's military statement says army chief Gen. Raheel Sharif denounced "such acts of sovereignty violations" as "detrimental to relations and counter-productive for the ongoing peace process." Sharif insisted that "Pakistan's efforts, successes and sacrifices in fight against terrorism have been unparalleled." Taliban leader Mullah Akhtar Mansour was killed inside Pakistan in the drone strike on Saturday that hit his vehicle in Baluchistan province. The airstrike strained relations between Pakistan and the United States. On Tuesday, Pakistan's Interior Minister Chaudhry Nisar Ali Khan condemned the drone strike and claimed that Mansour was not an obstacle to peace talks. Mansour was killed in Pakistan on Saturday when his vehicle was struck by a US drone plane, an attack believed to be the first time a Taliban leader was killed in such a way inside Pakistani territory. Pakistani authorities have been accused both by Kabul and the West of giving shelter and support to some Taliban leaders — an accusation that Islamabad denies. The insurgents have been fighting to overthrow the Kabul government since 2001, when their own regime was overthrown by the US invasion. The United States and the Afghan government have said that Mansour had been an obstacle to a peace process, which ground to a halt when he refused to participate in talks with the Afghan government earlier this year. Instead, he intensified the war in Afghanistan, now in its 15th year. Mansour had officially led the Taliban since last summer, when the death of the movement's founder, the one-eyed Mullah Mohammad Omar became public. But he is believed to have run the movement in Mullah Omar's name for more than two years. The revelation of Mullah Omar's death and Mansour's deception led to widespread mistrust, with some senior Taliban leaders leaving the group to set up their own factions. Some of these rivals fought Mansour's men for land, mostly in the opium poppy-growing southern Taliban heartland. Senior Taliban figures have said Mansour's death could strengthen and unify the movement, as he was in some ways a divisive figure. The identity of his successor was expected to be an indication of the direction the insurgency would take, either toward peace or continued war. Akhundzada is a religious scholar who served as the Taliban's chief justice before his appointment as a deputy to Mansour. He is known for issuing public statements justifying the existence of the extremist Taliban, their war against the Afghan government and the presence of foreign troops in Afghanistan. His views are regarded as hawkish, and he could be expected to continue in the aggressive footsteps of Mansour, at least in the early days of his leadership. He was close to Mullah Omar, who consulted with him on religious matters. A convincing orator, Akhunzada was born in Kandahar — the capital during the Taliban's 1996-2001 regime. A member of the Noorzai tribe, he is said to be aged around 50 years, and comes from a line of religious scholars. He leads a string of madrassas, or religious schools — figures in the Taliban say up to 10 — across Pakistan's southwestern Baluchistan province.