REUTERS

"The discussion is underway on the legal formula of a possible exchange. I do not rule it out, every opportunity to save the lives of our citizens should be used," Matviyenko said on Wednesday, TASS reports.

"Political will is needed on both sides for this to happen, and there is political will on our side," she assured.

On Tuesday, Ukrainian President Petro Poroshenko said that he and his Russian counterpart Vladimir Putin had managed to hammer out a certain model for the release of Nadia Savchenko.