Both Russian and Ukrainian presidents marked the occasion, with Vladimir Putin calling for a 36-hour ceasefire and Volodymyr Zelensky hailing Ukrainians for their fighting spirit.
Orthodox Christians packed churches on Friday evening for Christmas Eve services, a holiday overshadowed for many by the conflict raging between Orthodox neighbours Russia and Ukraine.
Patriarch Kirill, leader of the Russian Orthodox Church, the world's largest Orthodox denomination, led elaborate services at Moscow's Christ the Savior Cathedral, with dozens of priests and officiants arrayed in rich vestments swinging smoking incense censers and chanting the liturgy.
A day earlier, Kirill called for a 36-hour ceasefire in Ukraine, which Russian President Vladimir Putin agreed to but that Ukrainian officials scorned as an attempt to allow Russian forces to regroup.
Kyiv residents ventured out into a light dusting of snow to buy gifts, cakes and groceries for Christmas Eve family celebrations, hours after the cease-fire was supposed to have started.
In a video message, President Volodymyr Zelenskyy praised Ukrainians as “united as never before” and lamented that the conflict has forced many to abandon Christmas folk traditions that prohibit sewing and hunting.
“It is forbidden to sew and knit, but we weave camouflage nets and sew bulletproof vests, overcoming evil. Our ancestors did not go hunting in these days, but we fight so that we do not become prey and to defeat the beast,” he said.
Ukrainians, like Russians and Orthodox Russians in some other countries, conventionally observed Christmas on 7 January. But this year, the Orthodox Church of Ukraine, which is not aligned with the Russian church and one of two branches of Orthodoxy in the country, agreed to allow the faithful to celebrate on 25 December. Many did so, but others held to the old ways.
Putin attended services at the Annunciation Cathedral, one of several churches on the grounds of the Kremlin.