Ukrainian President Petro Poroshenko has said that he ordered the immediate resumption of talks with Russia regarding the return of Ukrainians who are held in Russian prisons and in occupied territories.

"I ordered the immediate resumption of negotiations with the Russian Federation regarding the return of those who are in Russia and those who are in occupied territories," he said during his visit to Odesa region on Thursday.

He said that Ukraine could not forget or betray them.

"The key point is that we promised that we would return several dozen Ukrainians who still remain in captivity, as well as the best of our fighters, special forces, National Guard servicemen. We will return all of them," Poroshenko said.

According to the president, Ukraine will fight for each of its citizens.

"This is a big contrast with the Russian Federation. We have a lot of their people which they say 'they are not there.' Nobody, including the president, cares about them. Their parents were told to forget about them. These are your children, husbands. This is the abyss that now distinguishes Ukraine from Russia. Take back [your people], just return our [citizens] Sentsov, Sushchenko, Kolchenko and many others," Poroshenko added.