Russia's defense ministry says its military at the Russian air base in Syria is preparing for some of the planes and fighter jets to leave and return home.

Tuesday's statement comes a day after President Vladimir Putin ordered the Russian military to withdraw most of its forces from Syria, timing his move to coincide with the resumption of Syria peace talks in Geneva.

The ministry says Russian personnel are currently loading equipment and materiel on cargo planes and getting ready for the withdrawal, which marks an end to Russia's five-and-a-half-month air campaign.

Russian air strikes have allowed Syrian President Bashar Assad's army to win back some key ground and strengthen his positions ahead of the Geneva talks.

The ministry did not indicate when the first planes are scheduled to leave.