“The esteemed Mullah Abdul Ghani Baradar has been appointed … chief of the political office,” Taliban spokesman Zabihullah Mujahid said in a statement released late Thursday.
“This step has been taken to strengthen and properly handle the ongoing negotiations process with the United States,” he added.
The announcement comes as the Afghan Taliban said Thursday they had held four straight days of talks with US officials in Doha.
The duration of the talks, described as “unprecedented” by analysts, has raised hopes of an imminent agreement that could pave the way to peace talks.
Afghan officials, who have complained previously about being cut out of the talks, also warned that any agreement would need their endorsement.
Baradar, formerly a number two of the group, helped Mullah Omar, who died in 2013, to found the Taliban movement.
He was arrested from Pakistan in February 2010.
Baradar was described as a “heavyweight” by Kabul-based military analyst Ateequllah Amarkhail, who noted that he also has influence over Mullah Muhammad Rasool, the leader of a Taliban breakaway faction.
“The appointment of Baradar could unify the Taliban movement,” Amarkhail told AFP.
In addition to the appointment of Baradar, “multiple changes have also taken place in the military and civilian departments”, the Taliban said in their statement.