Russia's energy minister Alexander Novak warned Friday of a high risk of disruptions to Russian gas supplies to Europe this winter as international tensions over Ukraine mounted.
"The situation is extremely critical as the heating season approaches," Novak said at a joint press conference with the EU's Energy Commissioner Guenther Oettinger.
"There is a high risk that gas delivered by Gazprom for Europe will be illegally taken by Ukraine for its own use," he warned.
Russia in mid-June cut its deliveries for Ukraine after a pro-Western government took power and disputes over prices led to what Novak said was the accumulation of a debt of $5.3 billion.
That decision heightened concerns about supplies to Europe as a major portion of Russian gas flows through Ukraine.
Russia is the EU's top supplier of gas. The 28-nation bloc depends on energy imports for more than 50 percent of its needs, and roughly 40 percent of those imports are supplied by Russia.
Moscow has a history of using gas prices as a political weapon and has twice shut off supplies to Ukraine in the past decade, causing supply disruptions to Europe in 2006 and 2009.
Ukraine has recently acknowledged that it does not have sufficient reserves to make it through the winter and accused Russia of wanting to cut supplies to Europe.
Novak called his two hours of talks with Oettinger constructive but did not announce any progress on resolving the price dispute with Ukraine.
For his part, Oettinger said that "to resolve the crisis one should not use gas as an instrument of sanctions and escalation."
He called for quickly creating a repayment schedule for gas delivered when prices were not under dispute.
Novak said that if Ukraine settles part of that debt, a "restructuring" of the other part could be considered.
Gazprom chief Alexei Miller, who was present during the talks, was quoted as saying by Russian news agencies that if some of the debt is repaid then it was willing to begin selling Ukraine gas on a pre-paid basis.
Norway, Europe's number two gas supplier, said it could compensate only somewhat for any decline in Russian deliveries.
"In the short term, during a crisis, we could increase (supplies) a bit, but over the longer term if we are to deliver more natural gas to Europe we need more pipeline capacity and a market that wants to buy the gas," Norway's Foreign Minister Boerge Brende said Friday at a conference in Oslo.
A cut-off of Russian gas that travels via Ukraine would impact most several southeastern European countries as they are highly dependent on these supplies and do not have other pipeline connections.