WikiLeaks says it is publishing more than 2 million emails from Syrian political figures dating back to 2006 but also covering the period of the crackdown on dissent by Syria's regime.

"Just now ... WikiLeaks began publishing the Syria files, more than 2 million emails from Syrian political figures, ministries and associated companies dating from August 2006 to March 2012," spokeswoman Sarah Harrison said on Thursday.

WikiLeaks founder Julian Assange said in a written statement: "The material is embarrassing to Syria but it is also embarrassing to Syria's external opponents.

"It helps us not merely to criticise one group or another but to understand their interests, actions and thoughts. It is only through understanding this conflict that we can hope to resolve it."

The news came a day after Russia denied having discussed with Washington offering exile to Syria's President Bashar al-Assad.