The head of Syria's powerful Al-Qaida branch on Friday urged opponents of President Bashar Assad to reject a ceasefire due to begin at midnight and instead intensify attacks on the regime.
"Beware of this trick from the West and America because everyone is pushing you to go back under the thumb of the oppressive regime," Mohammad al-Jolani, the head of Al-Nusra Front, said in an audio message.
"Fighters in Syria, willingly arm yourselves, intensify your attacks and have no fear of their troops and their aircraft," Jolani added.
Describing the truce as "shameful", the jihadist chief said that "negotiations are the ones conducted on the battlefield".
The ceasefire agreement brokered by Russia and the United States marks the biggest diplomatic push yet to help end Syria's violence, but has been plagued by doubts after the failure of previous peace efforts.