Patriarch Kirill of Moscow and All Russia wished Christians who celebrate the Nativity on Saturday "peace, joy, wellbeing and God's grace."
Roman Catholics, Lutherans, Anglicans and some Orthodox churches mark Christmas on December 25 in line with the Gregorian calendar.
The Russian, Jerusalem, Serbian and Georgian Orthodox churches, Athos monasteries, some Catholics and some Protestants celebrate the feast on January 7 in line with the Julian calendar.