WASHINGTON (AFP) - Taleban leader Mullah Akhtar Mansour was targeted and "likely killed" on Saturday in a US drone strike in a remote area of Pakistan along the Afghan border, a US official said.

The airstrike, authorised by President Barack Obama, also killed a second adult male combatant as the two travelled in a vehicle south-west of the town of Ahmad Wal, but no civilians were killed, the official said under condition of anonymity.

"Mansour was the target and was likely killed," in the strikes, which occurred around 6am (6pm Singapore time) and were carried out by multiple unmanned aircraft operated by US Special Operations Forces, the official said.

Pentagon spokesman Peter Cook said in a statement that Mansour "has been the leader of the Taleban and actively involved with planning attacks against facilities in Kabul and across Afghanistan, presenting a threat to Afghan civilians and security forces, our personnel, and Coalition partners."

Mansour was appointed head of the Taleban in July 2015 following the revelation that the group's founder Mullah Omar had been dead for two years.

"Since the death of Mullah Omar and Mansur's assumption of leadership, the Taleban have conducted many attacks that have resulted in the death of tens of thousands of Afghan civilians and Afghan security forces as well as numerous US and Coalition personnel," Cook said.

Officials were still assessing the results and would provide more information when available, he added.