Ahrar Al-Sham, the Saudi-backed militant organization announced that it will reject the ceasefire which is to enter into force on Monday, September 12.

The militant group, which has evaded being labeled a terrorist organization thanks to US veto in the UN Security council, announced that it will not comply with the ceasefire negotiated by US Secretary of State john Kerry and Russian Foreign Minister Sergey Lavrov.

The announcement has been made by the group's top ranking member on a video uploaded to their YouTube website. In the video, Ali al-Omar, group's deputy leader claims that the truce will only "reinforce" the government of Bashar Al-Assad and "increase the suffering" of civilians.

"The Russian-American deal… will send all the sacrifices and gains of our people who have risen up into smoke. It will only serve to reinforce the regime and surround the revolution militarily," al-Omar says in the video.

The Ahrar Al-Sham is a hardline opposition group known to be as close affiliate of the Jabhat Fateh al-Sham Front, formerly known as the Syrian al-Qaeda affiliate Al-Nusra Front, who also rejected the truce proposal.

"It's simple — the Russian-American deal is intended to eliminate those who protect Syrians," Fateh al-Sham spokesman Mostafa Mahamed said in his post on Twitter.

Earlier in May, Russia tried to add Jaysh al-Islam and Ahrar al-Sham to the list of terrorist groups because of their ties to Al-Qaeda and Daesh, but the US blocked the proposal.

Jabhat Fateh al-Sham (Al-Nusra Front) is labeled a terrorist organization and outlawed in Russia and the United States.