"We note with satisfaction that we have received an agreement in principle from Damascus to attend the international conference, in the interest of Syrians themselves finding a political path to resolve the conflict, which is ruinous for the nation and region," Russian foreign ministry spokesman Alexander Lukashevich told reporters.
Some European media have reported that the meeting has been tentatively scheduled to be held on June 10.
But Lukashevich said such reports "cannot be taken seriously" because the ranks of Syrian President Bashar al-Assad's foes remain so divided.
"Demands to immediately name a specific date for the conference without having clarity about who -- and with what authority -- will speak in the name of the opposition, cannot be taken seriously," Lukashevich said.
Syria's main opposition group entered a second day of talks Friday aimed at finding an approach to a joint Russian-US peace push aimed at getting all the sides involved in international talks that have been dubbed "Geneva 2".
The first Geneva meeting in June last year ended in a broad agreement aimed at forming a transition government in Syria and introducing a long-lasting truce.
But the deal was never implemented because of disagreements over Assad's role in the new government and the militant groups’ refusal to lay down their arms.