The U.S. conducted an airstrike Saturday against Taliban leader Mullah Mansour, the Pentagon said, and a U.S. official said Mansour was believed to have been killed.

Pentagon press secretary Peter Cook said the attack occurred in a remote region along the Afghanistan-Pakistan border. He said the U.S. was studying the results of the attack.

But a U.S. official not authorized to discuss the operation publicly said Mansour and a second male combatant accompanying him in a vehicle were probably killed.

The official said the attack was carried out by unmanned aircraft operated by U.S. Special Operations Forces. The official said the operation occurred at about 6 a.m. EDT southwest of the town of Ahmad Wal, and was authorized by President Barack Obama.

Mansour was chosen to take the helm of the Afghan Taliban last summer after the death several years earlier of the organization's founder, Mullah Mohammad Omar, became public. Mullah Omar's longtime deputy, Mansour had actually been the Taliban's de facto leader for years, according to the Afghan government.