Obama said in a statement that Mansour had rejected peace talks and had "continued to plot against and unleash attacks on American and Coalition forces".
"The Taliban should seize the opportunity to pursue the only real path for ending this long conflict - joining the Afghan government in a reconciliation process that leads to lasting peace and stability," he said.
The Taliban has been pushing Afghan security forces hard since the launch of their spring offensive in April, but the attack is likely to disrupt the movement, at least temporarily.
Although some individual Taliban members have been quoted in media reports saying that Mansour was killed, the movement's leadership, keenly aware of the need to limit damaging splits, has not issued its own confirmation.
"The leadership is being very careful because one wrong step could divide the group into many parties like former mujahideen," one Taliban official from the eastern province of Nangarhar said, referring to the guerilla leaders who fought the Soviet in the 1980s and '90s before splitting into warring factions.
A shura, or leadership council, has already begun meeting to choose a successor, a task that will be vital to protecting the unity of the movement.
One senior member of the shura based in the western Pakistani city of Quetta said that the choice appeared to be shaping around Mansour's deputy, Sirajuddin Haqqani, or a member of the family of the Taliban's founder Mullah Mohammad Omar, such as his son, Mullah Mohammad Yaqoob.
Haqqani, leader of an affiliated network blamed for a series of high-profile suicide attacks in Kabul, had the backing of Pakistan, while Yaqoob had support among members of the Afghan Taliban, the shura member said.
"We prefer someone from Omar's family to put an end to all internal problems," he said.
- AAP
