The head of the Orthodox Church called for a Christmas truce after Russian President Vladimir Putin ordered a 36-hour ceasefire.
Russian troops were ordered to hold their fire from noon on Friday until midnight on Saturday by Putin.
Mykhailo Podolyak is an adviser to Ukrainian President Volodymyr Zelensky.
He said that Russia must leave the occupied territories before it can have a truce.
The leader of the Russian Orthodox Church asked for a truce over the Christmas holiday. Christmas is celebrated in the Orthodox Church.
Kirill had been called a cynical trap by Podolyak.
The Minister of Defense of the Russian Federation was instructed by Putin to start a truce.
The Russian president said the ceasefire would allow those who are orthodox to attend services on Christmas Eve and the Day of the Nativity. He said that it was based on the fact that a lot of worshippers live in combat areas.
It is the first time that Putin has ordered troops to follow a ceasefire since Russia invaded Ukraine.
The idea of a Christmas ceasefire was not on the agenda at the time. He told reporters that no such offers had been made.
Kirill was an ally of Putin and supported Russia's "special operation" in Ukraine. He said in March that they had entered into a struggle that was not physical. Kirill told civilians to fulfill their military duty when Putin ordered a partial mobilization.
Turkey's president urged Putin to proclaim a ceasefire and open dialogue.