Russia's giant natural gas firm says it will sharply increase the price it charges Ukraine because negotiations on the matter have dragged on for nine months.
Gazprom Deputy Chairman Alexander Medvedev says the company plans to charge Ukraine a market rate of up to $230 per 1,000 cubic meters. Ukraine currently pays $50 in exchange for allowing the transit of Russian natural gas through its territory.
Officials from Ukraine's Naftogaz energy company call the latest price estimates unacceptable.
Russia initially wanted to charge Ukraine $160, but says that is no longer possible because of changing market situations.
Ukrainian President Viktor Yushchenko says the gas prices should not be used as a form of political pressure. He says Ukraine charges much less for transit than either Poland and Germany.
Some information for this report provided by AFP.