Ukrainian Justice Minister Pavlo Petrenko hopes that Ukrainian citizens Stanyslav Klykh and Mykola Karpiuk imprisoned in Russia will return home as part of the ongoing process of prisoner swap, in particular, within the Trilateral Contact Group on the settlement of the situation in Donbas.

"Nevertheless, I'm still full of optimism that there is a chance that those guys will also be brought back as part of prisoner swap, which is currently discussed in the Minsk Group," the minister told reporters, asked whether Ukraine continues to take measures to return Ukrainians convicted in Russia, including Klykh and Karpiuk, home, in Kyiv.

As reported, on May 26, 2016 the Chechen Supreme Court sentenced Mykola Karpiuk and Stanyslav Klykh to 22.5 and 20 years of imprisonment respectively. According to the verdict, Karpiuk is to spend first ten years of his sentence in a jail, while Klykh will spend first nine years, and subsequently they will be transferred to a maximum-security penal colony.

On October 26, 2016 the Russian Supreme Court upheld the verdicts for the Ukrainian citizens, who were convicted of fighting against federal troops during the first Chechnya campaign as part of the Ukrainian National Assembly-Ukrainian National Self-Defense (UNA-UNSO), which is banned in Russia.

On May 24, 2017 OSCE Special Envoy to the Trilateral Contact Group Martin Sajdik said that the parties to the Ukrainian conflict should update the lists of illegally detained persons during the week.

"We must update the lists during this week. It is a very difficult process, because there are various categories of detained persons," Sajdik told reporters following the Trilateral Contact Group's meeting in Minsk.

The Trilateral Contact Group is addressing these issues, he said.

"And, certainly, the rule of law [in Ukraine] needs to be respected. It is necessary that all procedures are implemented under such requirements," Sajdik said.

"We hope that the parties are indeed drawing nearer. I am proud to say that we're nearing the completion of the attestation [the verification of the lists of illegally detained persons] process," he said.

"I believe, it's quite a large number," Sajdik said, replying to a question as to what percentage of prisoners does not want to return to the territories beyond Kyiv's control.