KIEV, Ukraine — Russian and Ukrainian officials bickered into the night Friday over a deal leading to the resumption of Russian gas supplies, squelching hopes for an end to a dispute leaving parts of Europe in the cold and dark.
European Union representatives started work in Ukraine's capital, Kiev, to monitor the flow of gas, offering an independent assessment that was critical to sealing a bargain. But Russia said it would only restart pumping gas to Europe via Ukraine after a written deal is signed.
Russia wants monitors in place to prevent what it described as Ukraine's theft of supplies meant for Europe _ a charge Kiev hotly denies.
"Our goal is to show who is to blame for stealing gas," Russian President Dmitry Medvedev said. "Such thievery can't be left unaccountable."
Ukraine's President Viktor Yushchenko rejected the notion.
"Ukraine is not stealing gas," he told reporters angrily.
Gazprom halted all natural gas shipments through Ukraine on Wednesday, ending or reducing gas supplies to more than a dozen European nations amid a pricing dispute with Kiev.
Russia in the past has sold gas to Ukraine and some other ex-Soviet neighbors at prices significantly less than European prices.
Medvedev said Friday that Ukraine should pay a European price for the Russian gas. Last year, Russia charged Ukraine $179.50 per 1,000 cubic meters, about half what it charged its European customers.
Russia's last offer before talks broke down was $250, but Gazprom said the offer no longer stands after Ukraine rejected it and that it will charge Ukraine $450.
EU governments have criticized both Russia and Ukraine for the gas crisis, saying it was unacceptable to see homes unheated, businesses closed and schools shut down in the middle of winter because of the commercial squabble.
Russia, Ukraine and the EU all said the final agreement could be finalized soon, but officials remained coy about what prevented the deal from being completed Friday as hoped.
Ukraine's Natftogaz state gas company spokesman Valentyn Zemlyansky said it was resisting what he described as the Russian push for control over Ukraine's gas transportation network.
Gazprom's CEO Alexei Miller pledged Gazprom would resume shipments to Europe once the monitoring teams deploy to pipeline pumping stations across Ukraine _ a country roughly the size of South Africa or Texas.
But Medvedev emphasized that Russia will resume deliveries to Europe only after a written agreement is in place. "Regrettably, we don't have any faith left in Ukraine's good intentions," he said.
Czech Prime Minister Mirek Topolanek, whose country holds the EU presidency, visited Kiev on Friday to help wrap up the monitoring deal.
"We want to help overcome the crisis of confidence," Topolanek said after talks with Ukraine's president. "Russia wants to ship gas, Ukraine wants to transit it. This problem must be solved."
Yushchenko insisted that his nation "religiously fulfills its transit mission." "But there is one problem: this gas must be supplied from Russia," he said.
Ukraine had initially opposed including Russians in the EU monitoring team, but finally accepted their presence on Friday, Miller said. Ukrainian and the EU officials confirmed that Russians officials were welcome to join the mission.
"It is now imperative that the gas starts to flow," the EU said in a statement.
Once gas shipments resume, it "will take at least three days" for the first gas to reach European consumers, EU spokesman Ferran Terradellas said.
The halt in gas supplies has left European nations struggling to cope during a harsh winter. At least 11 people have frozen to death this week in Europe, including 10 in Poland, where temperatures have sunk to minus 13 F (minus 25 C).
Fifteen countries _ Austria, Bulgaria, Bosnia, Croatia, the Czech Republic, France, Greece, Hungary, Italy, Macedonia, Romania, Serbia, Slovakia, Slovenia and Turkey _ said their Russian supplies ceased Wednesday. Germany and Poland also reported substantial drops in supplies.
Ukraine's Naftogaz promised the first gas supplies would go to Bulgaria, where thousands of homes are without heating and factories have been shut.
The Sofia Zoo in the Bulgarian capital declared an emergency Friday after being left with no central heating. The zoo was using electric heaters for its 1,300 animals, some of which needed temperatures of at least 68 F (20 C), director Ivan Ivanov said.
Associated Press Writer Vladimir Isachenkov in Moscow contributed to this story.