Moscow/Kiev/Prague - Russia and Ukraine remained in a stand off on future gas prices on Friday but both parties separately sought to reassure Europe that the flow of gas through Ukrainian pipelines would not be disrupted.

Russian gas export monopoly Gazprom cut all supplies of gas to Ukrainian consumers on January 1 over non-payment and a failure to broker a new gas contract for 2009, placing in stark relief the EU's dependence on the free flow of gas through Ukraine for over a quarter of its needs.

A Ukrainian delegation to Prague on Friday failed to persuade the Czech presidency of the European Union to get involved in Ukraine's gas row with Russia as long as supplies to Europe remaine uninterrupted.

Czech government spokesman Jiri Frantisek Potuznik downplayed political aspects of the dispute between the two state-controlled gas giants Gazprom and Ukraine's Naftogaz, calling it "a bilateral row between two companies."

He added, however, that the EU is "ready to step in very quickly" if pressure drops in pipelines bringing Russian gas to the EU via Ukraine.

From Prague, the Ukrainian delegation led by Energy Minister Yuri Prodan would embark on a tour of European capitals for consultations on gas supply issues, the Czech Foreign Ministry said.

Officials at the Russian natural gas monopolist Gazprom said management was "taking a short break" to review the situation, and the total cut-off of supplies to Ukraine remained would in effect.

There was no indication of either side moving to resume negotiations.

On news of the Ukrainian delegation's tour, Russian Deputy Minister of Foreign Affairs Alexander Grushko said Gazprom executives were ready to head to Brussels and other EU capitals in their own efforts to lobby EU-member state governments.

Volumes of natural gas traveling to Europe were unaffected, according to principal European clients for Russian gas including Germany, Italy and Poland.

But the EU and United States have aired worries over the disputes and its implication for Europe's energy security.

Washington urged the Gazprom and Naftogaz to resolve their dispute over gas debt in a "transparent, commercial manner," US State Department deputy spokesman Gordon Duguid said.

The two state entities are in a complex deadlock over the price of future Russian supplies to Ukraine and tariff fees for on-shipment of gas to Europe.

Russian warned of significantly higher prices for Ukraine even as its offer for gas at 250 dollars per 1,000 cubic metres was rejected by Ukraine, which angled for prices between 200 and 210 dollars and an increase to the tariff shipment it charges Gazprom.

Gazprom also demands Kiev pay over 2 billion dollars in debt owed for November and December gas shipments.

Kiev acknowledges part of the debt, 1.5 billion dollars, which it said it transferred on Wednesday to RosUkrEnergo, a Swiss-based intermediary gas trader used by Gazprom to supply Ukraine.

But it rejects Gazprom's claims of another 600 million dollars in late-payment fees.

As sub-zero temperatures were felt in Kiev on Friday Ukrainian consumers had full access to gas in spite of the cuts.

The country's natural gas reserves could tide it over for at least 45 days, officials at Naftogaz said.

If Kiev decides to siphon Gazprom gas held in Ukrainian reservoirs sufficient volumes would be present to supply it for the entire winter, according to an Interfax news agency report.

Ukrainian security personnel on Thursday prevented Gazprom auditors from inspecting holding facilities containing gas owned by Gazprom, in a possible portent of Ukrainian intent to bleed off gas.

Similar Russian gas cuts to Ukraine in early 2006 sparked substantial reduction of supplies to Europe and price spikes across the continent.

Gazprom is currently pumping some 320 million cubic metres per day of gas for clients in Europe, over 80 per cent of which travel across Ukraine. (dpa)