The patriarch of the Russian Orthodox Church said in an interview broadcast on Thursday that Russia's military campaign in Syria is justified because it defends the Russian people.
"What is happening today in Syria ... is a defence of the fatherland," Patriarch Kirill said on state TV channel Russia-1.
Russia has flown an air campaign against rebel groups and terrorists in Syria since September in support Syrian President Bashar al-Assad, a longtime Russian ally.
If terrorist groups are allowed to gain power in Syria, they are likely to bring "misery and distress" to the Russian people, Patriarch Kirill told interviewer Dmitry Kiselyov.
Kiselyov, one of Russia's most renowned journalists, is also a staunch supporter of the country's President Vladimir Putin.
"As long as this war has a defensive character, it is justified," Patriarch Kirill said in the special program aired on Russian Orthodox Christmas.
The Russian Orthodox Church celebrates Christmas later than other branches of Christianity because it follows the Julian calendar, which has an exact 100 leap years for every four centuries. Today's most commonly used calendar, the Gregorian, has a more accurate 97 leap years for every four centuries.
The Russian state adopted the Gregorian calendar in 1918 following the communist revolution.