Russian President Vladimir Putin on Thursday ordered a 36-hour cease fire in Ukraine over Orthodox Christmas after an appeal from the head of the Russian Orthodox Church, a step Ukraine had earlier dismissed as a cynical trap.

Putin ordered the 36-hour ceasefire would begin at 1200 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.

"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.

A senior aide to Ukrainian President Volodymyr Zelensky, Mykhailo Podolyak, cast the Russian Orthodox Church as a "war propagandist" that had incited the "mass murder" of Ukrainians and the militarisation of Russia.

"The statement of the Russian Orthodox Church about the 'Christmas Truce' is a cynical trap and an element of propaganda," he said.