Russia is blocking negotiations on the release of detained persons, head of the Security Service of Ukraine Vasyl Hrytsak said, stressing that Ukraine is ready for unprecedented steps to free hostages.

"Unfortunately, to date, negotiations for the release of hostages are deliberately blocked by the Russian side and used as a means of political pressure," said Hrytsak at a briefing with Ukrainian Foreign Minister Pavlo Klimkin in Kyiv on Monday.

The head of the Security Service stressed that Ukraine is ready "for unprecedented steps" in order to "return all the prisoners home, both from the occupied territories - Crimea and Donbas, and from the territory of the Russian Federation."