The customs problems with Ukrainian goods at the Russian border mean that Russia has begun protecting its interests with regard to the prospects of signing a free trade agreement between the European Union and Ukraine, Vladimir Zharikhin, deputy director of the Institute of the CIS countries, said.

"What is now happening at the Russian-Ukrainian border is not a technical problem or a misunderstanding, but a protective measure used by Russia and the Customs Union," Zharikhin told Interfax on Friday.

Zharikhin said "Russia is finally convinced that Ukraine will not join the Customs Union, but will sign an agreement on free trade with the European Union."

The expert believes the actions taken by Russia are consistent, bearing in mind the position voiced by the Russian president a year ago.

"Ukraine's entrance in a zone of free trade with the EU means the removal of customs barriers for many goods. Bearing in mind that the Russian-Ukrainian border is virtually transparent, Russia in this situation simply has to put up a fence to protect itself and its partners in the Customs Union," the expert said.