Kiev - Ukrainian Energy Minister Yuri Prodan said on Wednesday reverse gas flows from the European Union to Ukraine had fallen because of opposition from Russian gas producer Gazprom.
Ukraine - which consumes around 50 billion cubic metres of gas annually - has increased its efforts to secure more gas from the European Union after Gazprom raised prices for its supplies in a dispute.
"Reverse gas supplies are reduced at present. This is linked to certain actions by Gazprom," Prodan told reporters, adding Ukraine first saw a decrease two weeks ago.
Gazprom declined to comment on Wednesday. The company said on April 5 the possibility of importing gas from the West to substitute for Russian supplies raised questions about the legality of such a move.
Gazprom head Alexei Miller has also called the reverse of gas flows from Slovakia to Ukraine "semi-fraudulent".
"You heard the threats Gazprom made to European energy companies that this reverse is illegal."
He said reverse supplies stood at 7 million cubic metres daily on Wednesday versus a possible 18 million. He did not say by how many supplies had fallen in the past two weeks.
On April 28 Bratislava and Ukraine signed a deal allowing the EU to send a limited amount of gas to Ukraine. Slovak Prime Minister Robert Fico said combined reverse flows from Slovakia, Hungary and Poland could reach up to around 16 to 17 bcm annually.