Russian President Vladimir Putin on Friday said that the peace process in Syria would be "complicated" but that there were no other ways of ending the conflict, ahead of the scheduled start of a ceasefire.

Russian President Vladimir Putin on Friday said that the peace process in Syria would be "complicated" but that there were no other ways of ending the conflict, ahead of the scheduled start of a ceasefire.

"We understand fully and take into account that this will be a complicated, and maybe even contradictory process of reconciliation, but there is no other way," Putin said in televised comments.

The Russian leader, however, insisted that there would be no let-up in Moscow's bombing campaign against Takfiri terrorist groups like ISIL and Nusra Front.

"I want to underline again that ISIL, Al-Nusra and other terrorist groups that have been designated as such by the United Nations Security Council are not included (in the ceasefire deal)," Putin said.

"The decisive fight against them will, without doubt, be continued."

The landmark "cessation of hostilities" pact brokered by Russia and the United States is due to take effect at 2200 GMT on Friday in a move that marks the biggest diplomatic push yet to help end Syria's violence.

Putin said that Moscow was already receiving confirmation from the warring sides that they were willing to abide by the ceasefire and that it would go into effect as planned.