"We are continuing talks by video conference," Moscow's chief negotiator Vladimir Medinsky said on Telegram. "Our positions on Crimea and Donbass have not changed."

Russian and Ukrainian negotiators held face-to-face talks in Istanbul on Tuesday. The talks provided a spark of hope for an end to the more than a month of fighting in Ukraine but there are few signs of attacks abating on the ground.

Earlier Friday a Russian governor accused Ukrainian helicopters of bombing a fuel storage depot in the western Russian city of Belgorod sparking a huge fire.

The incident marked the first time Russia has reported a Ukrainian air strike on its territory since President Vladimir Putin sent troops to Ukraine on February 24.

The Kremlin said the reported Ukrainian air strike will hinder new rounds of peace talks.