Ukrainian President Petro Poroshenko has said during a meeting with Vatican Secretary of State Cardinal Pietro Parolin that representatives of Vatican could join the negotiations on the release of Ukrainians who are held illegally in self-proclaimed Donbas republics and in Russia.

"We have agreed to coordinate our actions to engage the Holy See into humanitarian missions for freeing hostages," Poroshenko said at a joint briefing with Parolin in Kyiv on Friday.