The regime has come under fresh condemnation as Western officials raise concerns that Assad might use chemical weapons against rebels in an act of desperation.
The U.S. and NATO also say Assad's forces have fired Scud missiles at rebel areas.
Syria denied the Scud allegations. The government also has been careful not to confirm it has chemical weapons
At Thursday's hearings in Moscow, Bogdanov said the Foreign Ministry is preparing evacuation plans for thousands of its citizens, most of whom are Russian women, married to Syrian men, and their children.
Russia's ties to Syria date back to Assad's father, Hafez, who ruled from 1971 until his death in June 2000. In the last four decades, Russia has sold Syria billions of dollars' worth of weapons.