The UN-Arab League envoy on Syria, Lakhdar Brahimi, met Tuesday with Syrian opposition members based in Syria, dpa reported.
Brahimi met Hassan Abdel-Azim, the head of the National Coordination Committee for the Forces of Democratic Change, which, unlike the armed opposition in the country, is calling for political reforms and a peaceful transition.
The envoy was also expected to meet with Foreign Minister Walid al-Moallem, a UN source said.
Brahimi arrived in Damascus Monday as part of a regional tour ahead of peace talks planned in Geneva and aimed at ending the Syrian conflict, which by UN estimates has killed more than 100,000 people.
The UN envoy would meet President Bashar al-Assad Wednesday "if the meeting at the Foreign Ministry goes well," a Syrian security source told Lebanon's pro-al-Assad al-Mayadeen television.
Syria has accused Brahimi of being biased after he called for "real, not cosmetic change" in Syria this year and accused al-Assad of "resisting the aspirations of his people."
Al-Assad in an interview last week with al-Mayadeen said he would welcome Brahimi back to Damascus as long as "he sticks to his mandate and does not overstep it."
"He is tasked with a mediation mission," al-Assad said. "A mediator should be neutral."
Brahimi's visit, the first to Damascus since December, came as he hopes to press members of the opposition Syrian National Coalition to take part in the Geneva conference.
No date has been set for the conference, but the Arab League has said it might take place November 23-24.