Qatari Foreign Minister Khaled al-Attiyah said on Friday he opposed the creation of lists of opposition before peace talks on Syria.

"We are against the absolute classification of groups. What is more important is to understand the logic behind why these groups took up arms, their aims and motives," he told reporters at a news conference with his Russian counterpart in Moscow.

Russian Foreign Minister Sergei Lavrov said it was crucial to ensure that the widest circle of opposition members take part in future talks to end Syria's civil war.