Ukraine accused Russia on Sunday of deliberately reducing gas flows to customers in Europe.
"We consider the actions of Gazprom as threatening the energy security of Ukraine and Europe, which could bring unpredictable consequences for the entire gas transit system of Europe," Ukraine's state energy company Naftogaz said in a statement.??
"Naftogaz urges Gazprom to stop technical manipulation of volumes and gas supply routes, synchronize the work of the gas distribution systems of Russia, Ukraine and Europe and resume talks," the statement said.
Poland, Hungary, Romania, Bulgaria and Turkey have reported drops in supplies after Russia's state gas monopoly Gazprom cut off supplies to Ukraine earlier Thursday after the two sides failed to agree on terms for a 2009 contract amid conflicts over a new price and gas transit fees.
However, other EU member states like Germany, Turkey, Italy and the Czech Republic had not been affected by the dispute.
On Friday, Gazprom accused Ukraine of "stealing" gas in transit. Ukrainian officials denied the accusation, saying that Russia is not delivering the due quantities to European clients.
Around a quarter of the gas used in the union -- more than 40 percent of the bloc's imports -- comes from Russia, and Ukraine sits on the main transit route for gas exports, accounting for 80 percent of the continent's gas supply from Russia.
In 2006, a dispute over gas prices between Kiev and Moscow sent jitters among European customers after Gazprom cut all gas supplies to Ukraine.
(Xinhua News Agency January 5, 2009)