Russian energy giant Gazprom Monday decided to introduce pre-payment regime with Ukraine's Naftogaz company, as the latter failed to pay its multi-billion gas debt.
"The decision was made because of the chronic nonpayment by Ukraine's Naftogaz. Debt of the company for Russian gas deliveries stand at $4.458 billion," Xinhua quoted Gazprom as saying in a statement.
Naftogaz owes $1.451 billion for deliveries between November and December in 2013, and $3.007 billion for April-May this year.
Gazprom said it will supply gas to European consumers in full volume, but warned the European Commission (EC) of potential interruption in gas transit through Ukraine.
It also urged the Ukrainian side to abide by the obligations and ensure fluent gas transit, adding the company would file a suit in Stockholm court of arbitration against Naftogaz.
Russian Deputy Prime Minister Arkady Dvorkovich said further action regarding Ukraine's gas debt would be taken after Gazprom CEO Alexei Miller's report to President Vladimir Putin.
