A bitter dispute over natural gas prices between Russia and Ukraine shows no sign of ending before a Sunday deadline when Russia might cut off the supply of gas to its neighbor. The two sides remain far apart on plans by Russia to raise the price by more than four times the current charge.

Russia's giant energy company Gazprom rejected a last-minute appeal from Ukraine for an extension of the Sunday deadline to reach an agreement.

Ukraine's president, Viktor Yushchenko, has also sent a telegram to Russian President Vladimir Putin asking for talks to continue until January 10th.

The two presidents have already talked by phone seeking an end to the standoff between energy officials of both countries at a series of meetings.

Mr. Putin is quoted as saying there should be no cutoff in gas supplies, and President Yushchenko says Ukraine has enough gas in reserve to last out the winter.

Now European governments are also expressing concern that supplies to their countries may also be affected; Europe receives 20-percent of its gas from Russia, most through pipelines that cross Ukraine.

Gazprom demands that Ukraine pay the full market price of about 230 dollars per thousand cubic meters of gas, more than four times the current price of 50 dollars.

Ukraine says any price increase should come over a period of time to avoid a huge shock to its economy.

Russia says the disagreement is purely a commercial matter. But the bitter dispute comes a year after the Kremlin saw its preferred presidential candidate lose to the pro-Western Mr. Yushchenko in last year's Orange Revolution.

Gazprom is not making a similar demand of neighboring Belarus, which has remained loyal to Moscow despite its pariah status in the West as a dictatorship. Belarus pays even less than 50 dollars.

Boris Fyodorov is an official with Gazprom. He says that Gazprom is not asking for that much, nothing more than a company from an American or other country would ask for its product.

The two countries have long had a barter arrangement that dates from Soviet times in which Kiev receives a subsidized price in exchange for transit fees for gas pipelines across its territory.