Russian Foreign Minister Sergei Lavrov on Wednesday criticised the Friends of Syria grouping of Western and Arab countries opposed to the rule of President Bashar Al-Assad as negative for dialogue.

"Right now we see this process is making a negative contribution to the (Geneva) decisions," Lavrov told reporters in Istanbul in remarks translated to Turkish from Russian, referring to a 2012 accord among world powers in Geneva aimed at solving the Syria conflict through talks involving all parties.

"When one party is isolated in any mechanism set up to deal with a conflict, we miss the ground for dialogue."