Wednesday's statement said Assad had sent a letter to his Russian counterpart, Vladimir Putin, asking for the military support. Assad's Facebook page also reiterated that the support "came upon a request from the Syrian state," AP reported.
The statement came shortly after Russian lawmakers voted unanimously to let Putin send Russian troops to Syria. The Kremlin said it would only use its air force in the Mideast country, not ground troops.
Russia made the decision after considering that a large number of citizens of Russia and neighboring countries had gone to join terrorist groups fighting in Syria.
Kremlin said on Wednesday that unlike the US-led coalition of countries that bombs militant troops in Syria, Russia was invited to do so by the legal authorities of Syria and thus follows international law.