Russian officials are not responding to the proposals put forward by the Ukrainian delegation to the Trilateral Contact Group on Donbas settlement regarding the release of held persons.

"The Ukrainian delegation continues to insist on the need to release held persons as soon as possible, and is taking all the necessary measures to this end," the delegates reported via Facebook following the TCG's latest conference call on Wednesday, May 19.

"Unfortunately, the Russian side is so far reacting inappropriately to our proposals," the statement says.

The Ukrainian delegation says it continues to focus its efforts on the implementation of the following measures: ceasefire observance and improvement of the coordination mechanism for its maintenance; ensuring unimpeded access of the International Committee of the Red Cross and other international humanitarian organizations to held persons; release of held persons; unblocking by the Russian side of the crossing checkpoints' operation; ensuring free and unimpeded access of the OSCE SMM to the entire territory of Ukraine; as well as the admission of IAEA representatives to the occupied territories for inspections of nuclear facilities in the temporarily occupied areas.

Read alsoBellingcat identifies citizens of Russia involved in torture in Donetsk prison (Photos)At the same time, the position of the Ukrainian delegation is based on the fact that "it is critically important to return to full compliance with the ceasefire and strengthen effective control over its implementation."

"Progress on any other issues – political, humanitarian, and economic - and further coordination of the parties' steps remains problematic if the main, basic condition has not been fulfilled, which is a complete and comprehensive ceasefire," the TCG added.