Syrian President Bashar al-Assad has said a coalition between Syria, Russia, Iran and Iraq must succeed "or else the whole region will be destroyed".
Mr Assad also criticised the US-led coalition and its air strikes in Syria and Iraq as counter-productive, saying that terrorism had only spread.
Meanwhile, Russia has carried out more air strikes in Syria it says targeted so-called Islamic State (IS) positions.
Syrian activists say the raids appear to have focused on other rebel groups.