Al-Nusra Front, al-Qaeda's branch in Syria, will split from the terrorist network and change its name to Jabhat Fatah al-Sham (Front for the Conquest of Levant), its leader said in a video on Thursday.
The split is believed to have been prompted by intensified military campaigns separately launched by the United States and Russia against militant groups in Syria including al-Nusra Front and its rival Islamic State.
It was the first time that al-Nusra leader Abu Mohammed al-Jaulani appeared in a video with his face uncovered.
"The new formation aims at enforcing Allah's religion ... and working for unifying factions in order to cement the ranks of jihadists," al-Jaulani said in the video aired on Qatari television network Al Jazeera and other broadcasters.
He thanked al-Qaeda leaders for what he called "their understanding of the imperatives for disassociation."
Earlier Thursday, al-Qaeda's second-in-command, Ahmed Hassan Abul- Khair, endorsed the split in an audio recording released online.
Abul-Khair said that the unity of al-Nusra Front and the continuation of its battles in Syria are more important than links with the parent organization.
Al-Nusra emerged in Syria in early 2012, months after the eruption of an anti-government uprising that soon descended into civil war.
In 2013, al-Nusra pledged allegiance to al-Qaeda.
Al-Nusra has been designated since 2014 as a terrorist organization by the US - which broadly supports the opposition forces in Syria - and by the United Nations.
The White House was skeptical about the claims and said it would not change the complex situation on the ground in Syria.
"We judge any organization including this one much more by its actions, its ideology, its goals" than its affiliations, State Department spokesman John Kirby said, noting there was no reason to believe the group's objectives would change.