Former UN-Arab League envoy Kofi Annan says it's "too late" for military intervention in Syria and that providing arms to the opposition wouldn't put an end to the conflict, according to Reuters.

Annan resigned his position in August, blaming an instransigent Security Council for blocking the UN mission. He's calling for a political solution to the crisis, taking its lead from the agreement reached in Geneva last summer.

"I don't see a military intervention in Syria. We left it too late. I'm not sure it would not do more harm," he told an audience at the Graduate Institute, Geneva on Tuesday night.

"Further militarization of the conflict, I'm not sure that is the way to help the Syrian people. They are waiting for the killing to stop. You find some people far away from Syria are the ones very keen for putting in weapons.

"My own view is that as late as it is we have to find a way of pouring water on the fire rather than the other way around."

France and Britain have been leading calls on the EU to relax the arms embargo on the country and to allow them to send weapons to moderate factions within the Syrian opposition. In a paradigm similar to that which led the 2011 intervention in Libya, the US says it will back the Anglo-French effort.

According to Western Intelligence sources President Assad's regime is being propped up by Russia and Iran, with regular flights supplying Damascus with weapons and cash.