Iranian President Mahmoud Ahmadinejad, whose government supports the al-Assad administration, proposed the observation of a truce on Eid al-Adha, Iranian media outlets said.

"In our view, ceasefire and dialogue for free elections is the right solution," Ahmadinejad told reporters at the Asia Cooperation Dialogue summit in Kuwait City.

The U.S. election and the price of sitting out Syria.

Stop arming Syrians, Brahimi tells world

Brahimi backed U.N. Secretary-General Ban Ki-moon's call for countries to stop arming the different sides.

"God willing, this would be a start to get out of the Syrian crisis, and of course this won't be easy," he said to the Lebanese news outlet. "These countries should know that this crisis won't be confined within the Syrian borders forever. If not resolved it will deteriorate."

There is mounting concern over a foreign presence in Syria, such as Hezbollah and Iranians fighting for the al-Assad regime.

CNN has learned that British authorities think dozens of British citizens have gone to Syria, some of whose motivation is to wage jihad.

Not all of them are planning to join the Free Syrian Army, which is becoming increasingly hostile to the jihadist elements fighting al-Assad's army.

There are concerns that jihadists are getting battlefield training and experience in Syria that they could bring back and use on targets in Great Britain.