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.
As with the question of Syrian President Bashar al-Assad's fate, diplomats say it will be extremely hard to reach consensus on a list of rebel groups to be excluded and legitimate members of an opposition who would participate in the negotiations.
Syrian Foreign Minister Walid al-Moualem said on Thursday during a visit to Beijing that Damascus was ready to take part in peace talks in Geneva and hoped that the dialogue would help it form a national unity government.
The UN Security Council on Dec. 18 unanimously approved a resolution endorsing an international road map for a Syrian peace process, a rare show of consensus among major powers on a conflict that has claimed over a quarter of a million lives.