In particular, border guards of Kherson and Berdyansk units have spotted three Russian helicopters lurking along the administrative border without crossing it into mainland Ukraine.

They also observed a Rys-type reconnaissance balloon launched close to the border line.

Read alsoReuters: Tillerson says U.S. expects Russia to meet Ukraine commitmentsIn addition, border guards observed maneuvering by Russian military hardware and troops on their positions close to the administrative border.

As UNIAN reported earlier, 2017 would be an important year for the return of Crimea to Ukraine. Ukrainian president's envoy to the Crimean Tatar people and Crimean Tatar leader, Ukrainian MP Mustafa Dzhemilev named a catalyst that will push the process from a standstill. In his words, if Putin continues to behave the way he does, Russia will eventually fall apart.