Pakistan accused the United States on Sunday of violating its sovereignty with a drone strike against the leader of the Afghan Taliban, in perhaps the most high-profile US incursion into Pakistani territory since the 2011 raid to kill Osama bin Laden.

What does Mansoor's killing mean? Pakistan





It will be damaging to the Taliban-Pakistan relations since Islamabad has been hosting the Taliban leadership on its territory, as confirmed by Pakistan foreign affairs adviser Sartaj Aziz.



Islamabad has been under pressure by the Afghan and the US governments to use its considerable influence over the Taliban to bring them to the negotiating table.



More recently US politicians obstructed the sale of F16 jets and other military aid to Pakistan on the grounds that it has been harbouring Taliban and the Haqqani network. The US administration has been exerting pressure on Islamabad to put tangible pressure on the Taliban leadership to end its 15 years of armed rebellion.

Taliban



Mullah Mansoor’s death can be seen as both a challenge and an opportunity for the Taliban. The armed group could either split into several splinter groups, or the vacancy at the top could be used as an opportunity to rally around a more unifying leader. The new leader is most likely to come from the battlefield, a hardliner, which means more war.

Afghan government



It is a major psychological boost for the Afghan government. Analyst are of the opinion that if the Afghan government could service its own internal woes in 2016, that alone would be an achievement. The killing of Mansoor has thrown the government a lifeline. With the Taliban wounded, the Afghan government can only blame itself if it fails to put its house in order and come up with a quick military plan to go on the offensive.

Hashmat Moslih, Al Jazeera's Afghan analyst

Afghanistan said the attack killed Mullah Akhtar Mansoor, which, if confirmed, could trigger a succession battle within the armed group that has proved resilient despite a decade and a half of US military deployments to Afghanistan.

Afghanistan's Chief Executive Abdullah Abdullah said on Twitter that he was dead, the country's spy agency also said that he had been killed, and a source close to Mansoor told Al Jazeera he believed the reports to be true.

The Saturday drone strike, which US officials said was authorised by President Barack Obama, showed that the US was prepared to go after the Taliban leadership in Pakistan, which the government in Kabul has repeatedly accused of sheltering the rebels.

Pakistan protested on Sunday, saying the US government did not inform Prime Minister Nawaz Sharif beforehand.

"This is a violation of Pakistan's sovereignty," Sharif told reporters in London.

PROFILE: Mullah Akhtar Mansoor

A US official, speaking on condition of anonymity, acknowledged that Washington only notified Pakistan after the strike.

The Taliban, which has a history of denying developments that could hurt its standing, has not yet issued an official statement though some of the group's officials earlier denied the reports.

False rumours on the deaths of Taliban figures have circulated before. In December, the Afghan government said Mansoor had died after a gunfight. The Taliban later released an audio message from him in which he denied he had been killed.

US Secretary of State John Kerry said on Sunday that the Taliban chief posed a "continuing imminent threat" to US personnel in Afghanistan and to Afghans, and was a threat to peace.

"This action sends a clear message to the world that we will continue to stand with our Afghan partners as they work to build a more stable, united, secure and prosperous Afghanistan," Kerry said.

The US stopped short of formally declaring Mansoor dead, a day after announcing the strike.

"At this point, we're not quite prepared to confirm that he was killed, though it appears likely," US Homeland Security Secretary Jeh Johnson told "Fox News Sunday".

Passport recovered

It was unclear how long Mansoor might have been inside Pakistan before the strike. Pakistan's Foreign Ministry disclosed that a passport found at the site of the strike, bearing a different name, carried a valid Iranian visa.

It added that the purported passport holder was believed to have returned to Pakistan from Iran on Saturday, the day of the drone strike targeting Mansoor. Photos of the passport, bearing the name Wali Muhammad, seen by Reuters news agency showed a passing resemblance to some of the old photos available of Mansoor.

US officials said the strike happened at about 1000 GMT, which would have put it late on Friday night in the target area.

Several drones targeted the men as they travelled in a vehicle in a remote part of Pakistan near the border with Afghanistan, southwest of the town of Ahmad Wal, one US official said.

The Pentagon confirmed that the US army had tried to kill Mansoor, but gave no information about his condition.

Inside Story - Should the US negotiate with the Taliban?

Al Jazeera's Mohamed Vall, reporting from Kabul, said the timing of the strike was significant because the Afghan government warned it would take action against the group for not participating in the talks.

"They refused to show at the negotiating table, so the Afghan President recently said that now it's time for us to act and go after them. The Quadrilateral Coordination Group (QCG), made up of representatives from Afghanistan, Pakistan, China and the United States were urged to show their military role," he said

"If it is proved that Mullah Mansoor has died in the strike, it would be a major blow to the Taliban."

READ MORE: 'Serious steps' against Taliban on Afghan talks agenda

Efforts to broker talks between the Afghan government and the Taliban had already stalled after a suicide attack in Kabul last month killed 64 people and prompted President Ashraf Ghani to prioritise military operations over negotiations.

But Ghani's office said on Sunday that the removal of Mansoor could open the door to talks and that Taliban members who wanted to end the bloodshed should return from "alien soil" and join peace efforts.

Who is Mullah Akhtar Mansoor?

Mullah Mansoor was born in about 1965 in a small village called Kariz in the Maiwand district of Kandahar. He belongs to Afghanistan's Ishaqzai tribe.

He fought against Soviet forces in Afghanistan for a brief period and was a member of Harakat-i-Inqilab-i-Islami, a former paramilitary group formed by Maulana Mohammad Nabi Mohammadi to fight them.

One of his first jobs for the group was overseeing the security of Kandahar airport.

In 1996-2001, when the Taliban was in power, he oversaw the ministry of civil aviation.

He rose to the upper echelons after Mullah Akhtar Osmani, a senior Taliban military leader and a close associate of Mullah Omar, was killed by US-led coalition forces in 2006 and Mullah Dadullah Akhund, the group's top military commander, was killed in 2007 by British special forces.

Between 2007 and 2010 he was able to stake a claim for higher office when Mullah Abdul Ghani Baradar, the deputy of Mullah Omar, and Mullah Obaidullah Akhund, the Taliban government defence minister, were captured by the Pakistan Intelligence agency ISI.

In July 2015, Afghan intelligence said that Mullah Omar had been dead for two years. Within hours of that announcement, the Taliban reportedly held a meeting and elected Mullah Mansoor as leader. But his appointment appeared to expose fissures in the group.

A few months after his appointment, Taliban fighters seized the capital of Kunduz province after launching a daring raid from multiple directions. The attack was the biggest blow to President Ashraf Ghani since he took office a year before.

In December 2015, Afghan officials said Mansoor had died after a gunfight. The Taliban later released an audio message from him in which he denied he had been killed.

Mansoor refused to join any of the Quadrilateral Coordination Group (QCG) meetings, made up of representatives from Afghanistan, Pakistan, China and the United States and aimed at reviving a peace process.

After his persistent refusal to join talks, Afghan officials told Al Jazeera that action against the Taliban would be on the agenda for the fifth round of peace talks in early May.

US officials briefed the media on May 21 that a drone attack authorised by President Barack Obama had "likely killed" him and another Taliban member.

With additional reporting by Shereena Qazi.