International envoy on Syria Lakhdar Brahimi began a meeting with Russian Foreign Minister Sergey Lavrov on Saturday, Interfax news reported, after the opposition rejected an invitation from Moscow to attend talks.
Brahimi's meeting with Lavrov comes after the envoy finished a five-day visit to Damascus, during which he met with Syrian President Bashar al-Assad and opposition groups inside Syria tolerated by the regime.
Brahimi is expected to seek Russia's backing for a proposal to set up a transitional government in Syria as a step towards ending the conflict, which the opposition says has claimed more than 45,000 lives since March 2011.
Russia, a traditional ally and arms supplier of Syria, has repeatedly vetoed United Nations resolutions against al-Assad.
The visit comes also after Moscow extended an invitation for Ahmed Moaz al-Khatib, the head of the newly formed National Coalition of Syrian Revolutionary and Opposition Forces, to visit Moscow for talks.
"We will not go to Moscow," al-Khatib told broadcaster Al Jazeera, adding that Russia should apologize for its stance so far in the Syrian conflict.
However, al-Khatib said he would be ready for talks with Russia if there was a clear agenda.
The fresh diplomatic drive comes as government forces shelled areas in the Damascus suburbs and besieged a rebel-held area in the southern province of Daraa, the birthplace of the uprising against al-Assad, the Syrian Observatory for Human Rights reported.