"Let your fight be in the name of Allah and with the aim of establishing Allah's Sharia (law) as the ruling system," he said in an Internet video. "Do all that you can so that your holy war yields a jihadist Islamic state."
An array of forces opposing Syrian President Bashar Assad has been fighting the government for nearly two years though their interests lie more in a common enemy than a common goal. Some fighters have expressed support for a Western-backed government in exile while others are militant Islamists seeking to create a state in the image Zawahiri described, Middle East Online said Sunday.
Zawahiri also threatened France for its military intervention in Mali to beat back forces loyal to al-Qaida that had taken over large portions of the country.
"I warn France that it will face, God willing, the same [fate] faced by America in Iraq and Afghanistan," he said.