Ukrainian President Petro Poroshenko has asked the European Union and the United States to assist in bolstering control over the Ukrainian state border.

Poroshenko made the request in a telephone conversation with German Federal Chancellor Angela Merkel, the Ukrainian presidential press service reported on Tuesday night.

Speaking of the peace plan principles, Poroshenko mentioned "the creation of a ten-kilometer buffer zone along the border, the pullout of illegal armed units, the liberation of all the illegally occupied administrative buildings and the resumption of activities of local power bodies and central television and radio stations."

It is also necessary to decentralize the authorities and to hold early local and parliament elections, the president stressed.

"This framework will shape up the logic of our further steps targeting the peace plan implementation. The tripartite contact group will draw up its phases and schedule," the president emphasized.

German Federal Chancellor Angela Merkel supported the steps towards the implementation of the Poroshenko peace plan, the press service noted.