The US military has dealt a potential blow to the Taliban whose insurgent assaults pose a major obstacle to US hopes for ending the war in Afghanistan.

The US launched a drone strike against Taliban leader Mullah Akhtar Mohammad Mansour and a US official said Mansour was probably killed in the operation, which took place in a remote area near Ahmad Wal, a town in western Pakistan's Baluchistan province.

US President Barack Obama had authorised the operation, the official said.

The operation involved several unmanned US aircraft, and it struck a vehicle in which Mansour was travelling. A second passenger, who officials described as another combatant, also was probably killed, the official said, but a final assessment has not yet been made.


Pentagon press secretary Peter Cook said that Mansour had posed a danger to US and Afghan forces and to local civilians. "Mansour has been an obstacle to peace and reconciliation between the Government of Afghanistan and the Taliban, prohibiting Taliban leaders from participating in peace talks with the Afghan Government."

If confirmed, Mansour's death would be a significant development as Afghan Government troops, backed by a small contingent of US and partner forces, prepare to take on an emboldened Taliban during what is expected to be a punishing northern summer fighting season.

Mansour took on the public mantle as Taliban leader after the news broke that Mullah Mohammad Omar, the movement's iconic longtime chief, had died in 2013. While Mansour, a Taliban transportation minister, prevailed in the initial succession struggle, he faced significant rivalries within Taliban ranks and was said in unconfirmed reports to have been shot during a meeting of militants late last year.

At the same time, US and coalition officials have been surprised at how quickly he managed to overcome internal divisions within the group. Mansour repeatedly rebuffed outreaches from Pakistan and elsewhere that the Taliban enter into peace talks with the Afghan Government. Instead, according to US and Afghan military officials, he called on the Taliban to fight at least through this year to see whether the group could maximise its strategic bargaining position.

Andrew Wilder, of the US Institute of Peace and a longtime Afghanistan expert, said: "You could see some factional fighting that could take some pressure off the Government, but in general, I don't think it's going to lead to a significant reduction in the fighting. I think any successor is going to use the fight against the Government to unify Taliban factions around [his] leadership."

Meanwhile, one of the Isis' most hunted leaders delivered a rare speech that suggested the militants are feeling the pinch of recent territorial losses and the killing of key officials in US airstrikes.

Abu Mohammed al-Adnani, who is the chief spokesman for Isis (Islamic State) and a close aide to leader Abu Bakr al-Baghdadi, threatened Jews, pledged to defeat America and used typically defiant language to predict victory for the group's self-proclaimed caliphate.

But the defensive tone of the speech, delivered in an audio address posted on one of the Isis websites, suggested also that the militants are contemplating the prospect that their senior leadership will be wiped out and their last important cities be lost. "Do you think you have won because you have killed one or more leaders? It is a false victory," he said. "Even if we lose Raqqa or Sirte, we won't be defeated," he added.

There was also no claim of responsibility for the downing of the EgyptAir flight.

- Washington Post, Bloomberg