Iran aims to send missiles and drones to Syria and increase the number of its military advisers there to support President Bashar al-Assad in his battle against rebels, a senior Iranian official told Reuters on Friday.

"It is likely that Tehran will need to send military equipment, missiles and drones to Syria ... Tehran has taken all necessary steps to increase number of its military advisers in Syria and deploy forces," the official said on condition of anonymity. "Now, Tehran is providing intelligence and satellite support to Syria."