Ukraine's prime minister, Yulia Tymoshenko, gave assurances Saturday that Russia would not go ahead with a threatened cut in gas supplies next week.
"I am convinced that there will be no cut-off," Tymoshenko said at a press conference, without giving details.
She said that Russian gas giant Gazprom had not yet made a formal warning and that "no official document on this exists."
Gazprom warned Friday it would cut its supplies to Ukraine by 25 per cent from 0700 GMT Monday after talks on outstanding debts failed.
A spokesman for Ukrainian gas company Naftogaz, Valentin Zemlyansky, told AFP that fresh talks were underway in Moscow on Saturday.
However, Gazprom's spokesman Sergei Kupriyanov told AFP he had "no new information" on the crisis.
The European Commission and Gazprom's European partners, which receive a large part of their supplies though Ukraine's pipelines from Russia, were informed last week of the situation.
The dispute is over 1.9 billion cubic meters of gas deliveries worth around 600 million dollars (395 million euros) that Ukraine has not paid, Kupriyanov said.
Although Ukraine claims to have settled its debts for 2007, disagreements remain over a debt Moscow says Ukraine accumulated in recent months when Russia used its own gas to make up for a shortfall in less expensive Central Asian gas.
Russian natural gas accounts for around a quarter of Ukraine's gas imports, with the rest coming from former Soviet republics in Central Asia via pipelines that go through Russia. (AFP)
Russia won't cut gas, says Ukraine