Belarus has sent its deputy prime minister to Moscow in a last-minute effort to secure a deal on gas imports Russia has threatened to suspend.
Russia has been accused of using energy as a threat
Russian state-owned energy firm Gazprom has warned it will stop supplying gas to Belarus on New Year's Day unless it agrees to pay a higher price.
Belarus has in turn threatened to disrupt Russian gas supplies to Western Europe if this happens.
Gazprom earlier denied a new deal had been reached, as claimed by Belarus.
A spokesman for the firm, Sergei Kupriyanov, told Russia's NTV television channel, talks to resolve the dispute had yet to make any progress.
"We continued negotiations by telephone and through exchange of faxes with our Belarusian colleagues until 0100, but we did not get any result," he said on Sunday.
"Right now, we still have no contract."
Gazprom said the Belarusian delegation sent to negotiate the deal to Moscow was not senior enough.
Belarus' energy minister told the Reuters news agency First Deputy Prime Minister Vladimir Semashko was likely to secure a new deal during his visit to Moscow.
"It's not only my hope. It think it's a real [prospect]," Alexander Ozerets was quoted as saying.
RUSSIAN GAS COSTS FOR 2007
Ukraine: $130 for 1,000 cubic metres (was $95)
Georgia: $235 ($110)
Moldova: $170 ($160)
Belarus: Gazprom wants $105 ($47)
Azerbaijan: Gazprom wants $235 ($110)
Mr Semashko had earlier said on Saturday that a new deal had been reached with Gazprom.
But Gazprom, which wants to raise prices by 123%, denied any agreement had been reached and said talks would continue.
Both nations have accused each other of blackmail over the dispute.
About 20% of Russian gas exports to Europe pass through Belarus, the remainder through Ukraine.
It echoes a fierce row last year between Russia and Ukraine, and comes as Russia is pushing up prices for many of its customers.
Russia has been accused of using its energy muscle to re-impose its will on what is sometimes called Russia's "near abroad" - the countries that were once part of the Soviet Union.
Although some of the targeted countries, such as Ukraine and Georgia, have strained relations with the Kremlin, Belarus has historically remained an ally throughout the post-Soviet period.
Gazprom insists the planned rise from $47 to $105 merely reflects market prices.
However, as has been the case with Belarus, the price rises are often coupled to demands for shared ownership of those countries' gas or oil distribution networks.
A half-share in Belarus' gas monopoly Beltransgaz, which operates its own pipelines and Gazprom's export pipeline, is up for grabs - but only, says the government in Minsk, if the price of gas stays lower.
Russia's gas customers, meanwhile, are urging that a deal be struck as soon as possible.
European Union countries in particular are keen to avoid a repeat of the gas shortages which accompanied the Russia-Ukraine dispute.
At that time, Gazprom accused Ukraine of siphoning off gas meant for Europe, and is now warning Belarus against doing the same thing.