"For three years already, we have been receiving complaints and appeals from Russian citizens who were injured in Syria and cannot undergo medical treatment in Russia," Russian veterans said in a statement.
Following the reports on Russia and Israel's agreement, a top Iranian general initially brushed aside the possibility of withdrawal.
Why the Kremlin is using mercenaries to fight its foreign wars.
The Russian president has a new year's message for Syrian President Bashar al-Assad.
The Varshavyanka class are among the quietest in the world, according to the boasts of Russian state media.
The trend is a significant spike as the death toll exceeds the 36 estimated by Reuters to have been killed in Syria over the previous 15 months.
The Russia-backed Syrian military and its allies entered ISIS-held Raqqa, where U.S.-backed forces are battling the jihadis.
Russia suggested President Donald Trump had no clear strategy in Syria after the U.S. leader said an apparent chemical attack changed his views on Syrian President Bashar al-Assad.
"If necessary, literally within a few hours, Russia can build up its contingent in the region to a size proportionate to the situation developing there," Putin said.
Having failed to knock out Ukraine with one big punch, Putin hopes to kill it with a thousand cuts.
Putin sees nothing strange about Russia destabilizing countries because "everyone" does it.
Tehran thinks deep economic ties with its neighbors can prevent more sanctions.
Putin may have insisted on new Iranian forces before committing his air force.
Assad is more confident in his regime's strength, and the Kremlin seeks to heighten its diplomatic cred.
Though Putin may look like he's in control in Syria, the intervention is likely to end badly for him.
NATO urged Russia to stop hitting opposition and civilians and focus on combatting ISIS
Stepping up support for extremists simply because Russia has targeted them would be folly.