Patriarch Kirill of Moscow called earlier on Thursday for both sides of the war in Ukraine to observe a Christmas truce.
A 36-hour ceasefire order in Ukraine has been given by Russian President Vladimir Putin on Thursday, Jan. 5, over Orthodox Christmas.
This is the first major truce of the more than 10-month long war.
Putin ordered the ceasefire to begin on Jan. 6, the Kremlin said.
Many Orthodox Christians, including those living in Russia and Ukraine, celebrate Christmas on Jan. 6-7.
Patriarch Kirill of Moscow called earlier on Thursday for both sides of the war in Ukraine to observe a Christmas truce.
"Taking into account the appeal of His Holiness Patriarch Kirill, I instruct the Minister of Defence of the Russian Federation to introduce a ceasefire regime along the entire line of contact of the parties in Ukraine from 12.00 on January 6, 2023, to 24.00 on January 7, 2023," Putin said in the order.
Statements from the Kremlin invariably use Russian time.
"Proceeding from the fact that a large number of citizens professing Orthodoxy live in the areas of hostilities, we call on the Ukrainian side to declare a ceasefire and allow them to attend services on Christmas Eve, as well as on Christmas Day," Putin said.
Ukraine earlier dismissed Kirill's appeal, though there was no immediate reaction to Putin's ceasefire announcement.