The EU's brand new Czech presidency was forced to issue a late-night call for the 'immediate resumption' of full gas supplies following falls in deliveries to Poland and Hungary - with the European Commission saying the latter was down 25 per cent.

The Russian accusation - which followed the New Year's Day cutting of supplies for the Ukrainian market in a row over unpaid fines and levies imposed by Moscow - had prompted a sharp denial by Kiev, which said it was dipping into its own reserves to honour obligations to the EU.

'The European Union calls for an urgent solution to the commercial dispute on gas supplies from the Russian Federation to Ukraine, and for an immediate resumption of full deliveries of gas to the EU member states,' the EU presidency said in a statement.

'Energy relations between the EU and its neighbours should be based on reliability and predictability. Existing commitments to supply and transit have to be honoured under all circumstances,' it added.

The commission said that it had received reports from Hungary and Poland of 'irregularities in gas received through the Ukrainian gas pipelines'. Hungary has seen a drop of around 10 million cubic metres, almost a quarter of the contracted supply, although Poland's national gas distributor Gaz-System said a six per cent fall there was being compensated by increased deliveries of Russian gas via Belarus.

Brussels did not apportion blame for the supply drop.

European Union states depend on Russian gas, much of which flows through Ukraine via a Soviet-built pipeline network.

Prague earlier proposed setting up independent monitoring stations on the Ukrainian-Russian and Ukrainian-Polish borders.

Both sides in what Czech Prime Minister Mirek Topolanek termed a 'commercial dispute' have sent delegations to Prague and other European capitals to put their case before EU politicians.

Deputy ambassadors from across the EU are also to discuss the crisis in Prague on Monday.

In televised comments, a spokesman for Russian gas giant Gazprom, Mr Sergei Kupriyanov, asserted: 'The Ukrainian side openly admits it is stealing gas and has no shame about it.' He put the amount of gas he said had been illegally 'siphoned' from pipelines crossing Ukrainian territory at 21 million cubic metres since Thursday.

He added that Ukraine was refusing to permit Russia to send the full amount of gas required for clients in Europe across Ukrainian territory on Saturday.

'Regarding the next 24 hours, the Ukrainian side did not agree to the transit volume required by us. We made a request for 303 million cubic metres but were refused and were permitted 296 million cubic metres,' he said.

Russian Deputy Foreign Minister Alexander Grushko said Moscow wanted to put its case before an emergency session of the European parliament 'to give the Russian side a chance to express its views'. But Ukrainian state energy company Naftogaz denied Gazprom's accusations and said Russia had reduced the amount it was sending through Ukraine.

It added that Gazprom had failed to provide 'technical' gas needed to maintain pressure in the pipeline network.

'We haven't received 17 million cubic metres of gas that was due,' Naftogaz spokesman Valentin Zemlyansky told AFP, explaining that Ukraine had added 10 million cubic metres of its own gas to deliveries to Europe.

'We are not stealing gas,' he said.

Mr Kupriyanov said Gazprom had increased supplies through Belarus, which normally handles about 20 per cent of Russia's gas shipments to European customers.

While both sides have voiced willingness to negotiate, Gazprom's chief executive Alexei Miller has scotched hopes of a quick deal, saying Ukraine would have to pay a 'European price' of US$418 per 1,000 cubic metres of gas in 2009, more than double what it paid last year.

Gazprom is demanding payment by Ukraine of over US$2 billion (S$2.9 billion), for gas supplied in November and December as well as fines for late payment.

Experts say both Ukraine - which wants EU integration - and the European Union are cushioned by large gas reserves they have built up in storage facilities.

Gas shortages occurred in Europe after a similar 2006 dispute.

Around a quarter of the gas used in the EU - more than 40 per cent of the bloc's imports - comes from Russia, most of it pumped in pipelines through Ukraine.

Russia earlier offered Ukraine a price of US$250 which Kiev turned down, arguing it should receive an increase in payments for gas transit.

The price of US$179.5 that Ukraine paid in 2008 is well under the amount paid by European countries for Russian gas. -- AFP