Ambassador Sajdik / Photo from unmultimedia.org

"I call upon the sides to provide conditions of dignity and respect for each of the persons to be exchanged," he said in a statement published on December 26.

Read alsoKremlin silent on possibility of releasing Sentsov, other political prisoners in prison swap effort"I welcome that the sides have agreed to conduct an exchange of detainees on December 27 – a step long awaited by the prisoners and their families. This is a deeply humanitarian gesture, even more so on the occasion of Christmas and New Year," he said.

Ukrainian envoy to the Minsk Trilateral Contact Group's humanitarian subgroup Iryna Gerashchenko said that 170 Ukrainian citizens are held captive by Russian-controlled militants in occupied Donbas.

The Ukrainian side is ready to swap 306 persons imprisoned in Ukrainian-controlled territory for 74 Ukrainians held hostage in occupied Donbas.