KIEV, Feb. 28 - A day after Ukraine paid most of its 2007 natural gas debts, Russian gas giant Gazprom accused the country of incurring $600 million debt for gas supplied in January and February.

Ukraine paid a total of $764 million in several installments over the past two weeks, including $480 million on Tuesday and Wednesday, saying it had paid all of the 2007 debt except for the disputable portion.

But Gazprom said Thursday the payments were not enough and urged Ukraine to send more money, including for natural gas consumed in January and February, potentially opening a new dispute.

"We have not yet seen any intention by the Ukrainian side to sign the documents for the repayment of the debt accumulated from the beginning of the
year, nor have we seen agreement on future gas supplies," Sergei Kuprianov, a spokesman for Gazprom, said in a statement.

"The situation regarding the export of Russian natural gas to Ukraine is complicated," he said.

Gazprom warned Ukraine on Tuesday that it may cut gas supplies to the country by 25% on March 2 if the country fails to make the debt payments.

"The fact is that, from the beginning of this year to date, Gazprom has supplied 1.9 billion cubic meters of gas to Ukraine," Kuprianov said. "The outstanding amount due is around $600 million."

Ukraine usually consumes cheaper gas produced in Turkmenistan that Gazprom buys and later re-sells to RosUkrEenrgo, the only supplier of the imported gas to Ukraine.

But Gazprom insisted that since the beginning of the year, it had been also selling its own, more expensive gas, completing short supplies from Turkmenistan, suggesting Ukraine should pay more as the price of the Russian gas was almost twice as high as the Turkmen gas.

"It is worth noting that Gazprom complements the gas to be exported from Central Asia to Ukraine out of its own Russian sources," Kuprianov said. "This is almost one quarter of the total gas amount supplied to Ukraine in January and February."

The Ukrainian government refused to accept the higher price, adding it was impossible to prove that the gas had actually come from Russia, not Turkmenistan.

A Ukrainian official said that nobody had ever asked Gazprom to send its own, more expensive gas to Ukraine.

But Gazprom has an answer.

"Why has Gazprom then continued to supply gas to Ukraine? The answer is simple: we understand Ukraine's need for natural gas, we have the ability to provide it," Kuprianov said. "We have been a reliable supplier for many years." (tl/ez)