Gazprom draait gaskraan Oekraïne mogelijk maandag dicht (en)
Russian gas firm Gazprom could turn off the tap to as much as a quarter of Ukraine's gas supply from next Monday if the country does not pay down its outstanding debts.
Ukraine owes the company some €1.04 billion.
However, the company has assured European officials that supplies to the EU will not be affected by any such move.
"Gazprom has given assurances that gas supplies to the European Union will not be interrupted," energy commissioner Andris Piebalgs said on Thursday (6 February), reports Reuters.
Ukraine receives much of its gas supplies from Central Asian sources, with Russian gas providing a stopgap to any reduction from its main suppliers. In January, this amounted to a quarter of the gas it received, due to particularly cold weather in Central Asia.
Gazprom stressed that it would be "forced to cut supplies of Russian gas" if the country did not resolve its debts, meaning that only the supply of Russian gas would be halted, while gas from Central Asia would continue.
The Russian gas giant, which is the world's biggest extractor of natural gas in the world and Russia's largest company, also cut supplies to Ukraine two years ago.
In 2006, Gazprom cut gas exports to Ukraine following a dispute over pricing and the cost of transiting the gas to Europe.
The current dispute is of particular concern to Europeans, as some 80% of Russian gas supplied to Europe comes via Ukraine.
In January, Ukraine's debts to Gazprom ballooned by €346 million, prompting the company to issue the warning.
Nonetheless, Gazprom is not demanding immediate payment of Ukraine's entire €1.04 billion debt. The firm has said it only wants an agreed schedule of payments for the additional €346 million in gas debts.