Moscow/Kiev - Russia on Saturday approved a European Union initiative for international observers to monitor Russian gas deliveries via Ukraine, raising hopes of a possible end to a Kremlin embargo on energy supplies to Europe.

But the mandate - a key demand by Moscow to lift its embargo of gas supplies - must still be approved by the Ukraine.

Czech Prime Minister Mirek Topolanek, whose country currently holds the EU presidency, signed the agreement with Russian Prime Minister Vladimir Putin on Saturday afternoon.

Topolanek was expected to travel to Kiev on Saturday evening to push for a way out of the crisis depriving Europe of gas in the dead of winter, Ukrainian officials said.

Prior to traveling to Kiev, Topolanek said the deal has been verbally approved by Ukrainian leaders President Viktor Yushchenko and Prime Minister Yulia Tymoshenko.

"I think there won't be any obstacles to (the mandate) being signed by Ukraine," he said at a press conference in Moscow.

Earlier, Topolanek promised to "stay in the region until we get the gas flowing."

The EU observation mission on Saturday had already begun work, inspecting Ukrainian gas transportation records and monitoring equipment in the capital Kiev. They were scheduled to tour Ukrainian natural gas transport or storage sites in the cities of Lviv, Uzhgorod and Odessa on Sunday, the Interfax news agency reported.

Volodymyr Trikolich, a spokesman for Ukraine's natural gas transportation company Ukrtransnafta, said Russian observers who were part of the expert team would also receive full access to Ukrainian installations.

The advance team of eight EU technicians arrived in Ukraine on Friday as part of the Brussels plan to end bickering between Kiev and the Kremlin over natural gas shipments.

A total 18 observers will work in Ukraine until the stand-off between Russia and Ukraine over gas shipments is resolved, EU officials said Friday.

The Russian natural gas monopolist Gazprom announced hours after the Putin-Topolanek signing ceremony that it had increased pressure in gas lines leading into Ukraine as a "sign of good will." If Ukraine were to sign the EU crisis resolution plan then Russian gas could reach Europe in full volumes within 48 hours - provide the Ukrainians "stole no more gas," Gazprom chairman Aleksei Miller said.

Putin in remarks after the Moscow signing accused Ukraine of enforcing "a gas blockade" of Europe by siphoning Russian gas destined for EU customers. The signed accord was essential to control any future stream of gas reaching Europe, he said.

Ukrainian officials have reject claims of siphoning, saying Russian gas was diverted to maintain pressure in the gas lines, and that no Russian gas has been consumed by Ukraine since the beginning of 2009.

Gazprom officials and Ukrainian negotiators on Saturday were still far apart on a critical contract for Russian natural gas deliveries to and through Ukraine during 2009. Ukrainian officials in past days have repeatedly stated they would not accept Russian gas shipments without a Russo-Ukrainian delivery contract signed and delivered.

The EU plan pushed by Topolanek would if effective resume Russian deliveries to Europe, while leaving open terms for future Russian deliveries to Ukraine.

The Russo-Ukrainian talks had stalled because the Russian delegation was insisting on fixing the price of natural gas to Ukraine for the duration of 2009 at 450 dollars per
1,000 cubic metres - the maximum price paid currently in Europe, and substantially above the expected price of gas as energy costs are predicted to fall substantially throughout 2009.

Putin argued the hardline Russian position was for Ukraine's good, saying in part, "Our actions do not aim to worsen but rather to help Ukraine get rid of crooks and bribe-takers and make its economy more transparent."

Russia in retaliation for Kiev's alleged gas theft began reducing its shipments to the former Soviet state on January 1, and by Wednesday, the Kremlin had halted all gas exports.

The crisis over gas was growing severe across Europe by the weekend, with record low temperatures covering the continent, and Balkan nations particularly reporting low or empty gas reserves.

Ukraine reportedly was relatively well-stocked with gas, holding between one and four months of its own reserves. Natural gas deliveries have continued unchanged to homes and residences since the first days of the Russian embargo, but in recent days some state- owned industrial firms have reported slowdowns or halts due to natural gas shortages.

EU member states in central and southern Europe continued to be hard hit by Russia's shut-off of all gas supplies through Ukraine, with Slovakia relying on gas supplies from Poland and EU neighbour Serbia seeking emergency help from Germany, Austria and Hungary.

By far the most critical situation, though, is faced by the Balkan nations Bulgaria, Serbia, Bosnia-Herzegovina, Macedonia and Moldova, which have no reserves left.

Ukraine's government on Saturday afternoon announced it would sell Moldova and Bulgaria gas from its own reserves. The gesture drew a retort from the Kremlin that Ukraine should send such nations Russian gas as contracted.

About a quarter of the EU's gas needs are met by Russian gas, 80 per cent of which reaches European clients via Ukraine. (dpa)