Ukraine's military says that one of its soldiers has been killed and four wounded amid multiple cease-fire violations by Russia-backed separatists in eastern Ukraine in the previous 24 hours.
A Defense Ministry statement said the separatists violated the cease-fire 15 times using mortars and heavy artillery.
Separatists, meanwhile, claimed that government forces violated the cease-fire 36 times using assault rifles, grenade launchers, mortars, and artillery.
Fighting between Kyiv's forces and the Russia-backed separatists who hold parts of the Donetsk and Luhansk regions has killed more than 10,300 people since April 2014.
Several cease-fire deals announced as part of the Minsk accords -- September 2014 and February 2015 pacts aimed to resolve the conflict -- have failed to hold.
Rights groups and Western officials have voiced alarm about a recent increase in hostilities.
At a meeting in Minsk on December 20, representatives of Russia, Ukraine, he separatists, and the Organization for Security and Cooperation in Europe (OSCE), affirmed their "commitment to a comprehensive, sustainable and unlimited cease-fire" starting at midnight on December 22-23.
The cease-fire was agreed "in connection with the forthcoming Christmas and New Year festivities" and existing agreements and obligations, it said.
The participants also reiterated that they hope to implement an exchange of detainees "before the New Year and Christmas holidays."
Ukrainian and Russian Orthodox Christians celebrate Christmas on January 7.