Ukraine should stick to its contractual obligations with regards to the volume of the purchased Russian gas and give up reverse gas shipments from Europe, Gazprom CEO Alexei Miller said at a press conference on Friday.

"We have a take-or-pay condition in our contract. This obligation extends to Naftogaz Ukrainy," he said.

"As for the reverse [gas shipments from Europe], Ukraine has no right to dispose of Russian gas on its territory as if it were their own. Any virtual reverse is illegal," the Gazprom CEO said.

According to him, Gazprom will take appropriate actions if Ukraine makes any illegal steps.