Russia hosted closed-door talks Monday with Syrian diplomats in a renewed push for a Syrian peace conference in which Moscow says Tehran also must play a role.
President Bashar al-Assad's envoys began negotiations in Moscow just as U.N. chief Ban Ki-moon disclosed in Vilnius that he hoped to convene the so-called Geneva II conference in mid-December.
Russian Deputy Foreign Minister Mikhail Bogdanov said his government "regards Iran as a very important partner in all Middle Eastern affairs,'' in comments at the start of separate talks with Iran's Deputy Foreign Minister Hossein Amir-Abdollahian.
The Syrian opposition said Russia also invited Syrian National Coalition president Ahmed Jarba for a three-day visit to coincide with the regime officials' stay.
Moscow has been emboldened by its success in helping to mediate a deal under which Syria will destroy its chemical weapons, but Washington is wary of allowing Iran to join Syrian peace talks.
Reuters reported that Syria's ambassador to Russia said Monday that insufficient funding and unspecified actions by militants fighting to oust President Bashar al-Assad are hindering the government's compliance with a deal to abandon chemical weapons
In Syria, a prominent rebel commander died after being wounded last week in the heavily contested northern city of Aleppo. Abdul-Qadir Saleh was the head of the Islamist al-Tawhid Brigade, which announced his death in a statement Monday.
He had been taken to a hospital in Turkey following an attack on the brigade' leadership by Syrian forces last Thursday that also killed another commander. The group is estimated to have at least 8,000 fighters.
Assad's troops have made recent gains in Aleppo, the country's largest city.