MOSCOW (AFP) - Russia on Sunday said a deal to resume gas supplies to the European Union through pipelines in Ukraine had been delayed as swathes of central Europe and the Balkans remained without heating. After days of wrangling, Russia and Ukraine signed an EU-brokered accord this weekend to deploy international monitors to verify the flow of Russian gas destined for European consumers via pipelines running through Ukraine. But Russian President Dmitry Medvedev said energy giant Gazprom would only resume supplies once Russia had a copy of the document signed by Ukraine and once the various teams of international observers were in place. "We will resume transit only under these two conditions," Medvedev said at a meeting broadcast on state television. "We are ready to do it as soon as all the conditions are fulfilled. The quicker this is done, the easier it will be to resolve the situation that Ukraine has created for European consumers," Medvedev said. Gazprom also said Ukraine was delaying a resolution. "We have still not received through official channels a copy of the monitoring agreement for Russian gas through Ukraine signed by all sides. This is delaying our work," Gazprom spokesman Sergei Kupriyanov said on television. Bogdan Sokolovsky, an energy aide to Ukrainian President Viktor Yushchenko, dismissed Russia's claim that it had not yet received the signed transit monitoring document as "lies," adding: "There's something wrong here." Meanwhile the first two international observers " from France's GDF Suez and Germany's E.ON Ruhrgas " arrived at the Sudzha gas measuring station in southwest Russia on the border with Ukraine. "The purpose is to establish this monitoring process. But it's not a matter of a few hours," said the representative of E.ON Ruhrgas, who declined to be named, as he travelled from the Ukrianian capital Kiev to Sudzha. The text of the accord signed Sunday calls for the EU, Russia and Ukraine to each provide 25 experts to "carry out checks on the basis of equal parity both on Ukrainian and Russian territory," the Ukrainian presidency said. Hundreds of thousands of people were left without heating this week after Russia cut off supplies to Europe through Ukraine, saying it was forced to do so because Kiev was blocking transit of the gas " a charge denied by Ukraine. The Russian newspaper Kommersant said an end to the cut-off was in sight but predicted EU states would in future unite to lessen dependence on Russian gas by increasing nuclear power and using gas from North Africa and Central Asia. "From tomorrow, Gazprom's gas transit to the European Union could be renewed and the gas war will return to being a propaganda one," Kommersant said. "The EU will undoubtedly try to find ways of reducing dependence on Russian gas supplies and avoiding such crises in future," the paper said. In Brussels, European Commission president Jose Manuel Barroso welcomed the deal brokered by Czech Prime Minister Mirek Topolanek, holder of the EU presidency, in Moscow and Kiev and called for supplies to be resumed quickly. "This should now finally allow the resumption of gas supplies from Russia to the EU.... There are many EU citizens at risk without gas supply and this situation has gone on for far too long," Barroso said. The gas crisis has taken a heavy toll on around a dozen states, notably in central Europe and the Balkans, which are highly dependent on Russian gas supplies, forcing factories, schools and public facilities to close. Europe depends on Russian supplies pumped through Ukraine for around a fifth of its total consumption. Some Russian gas is also pumped through Belarus and Turkey is connected to the Blue Stream pipeline from Russia. Demonstrating the far-reaching effects of the crisis, Budapest on Sunday announced traffic restrictions to reduce pollution levels prompted by major industries having to switch to oil consumption as a result of gas shortages. And Slovakia reopened a nuclear power plant it was forced to shut down as part of its bid to join the European Union, prompting condemnation from neighbouring Austria, which described the reactor at Bohunice as "unsafe."