Russian President Vladimir Putin has had a telephone conversation with his Ukrainian counterpart Petro Poroshenko, Putin's press secretary Dmitry Peskov said.

"The chiefs of state conferred on pressing issues of Russian-Ukrainian bilateral relations," he said.

"They touched upon the possibility of ceasefire in the combat zone in southeastern Ukraine," Peskov noted.

"Putin expressed concern in connection with the tragic death of Russian journalists in the vicinity of Luhansk and emphasized the need for the unconditional security of media representatives working in the conflict zone in Ukraine," Peskov stressed.

"Poroshenko presented condolences over the death of representatives of the Russian media and assured Putin he would order an inquiry and take relevant measures towards the security of journalists," the Russian presidential press secretary said.