Adam Arnold, Sky News Online
Belarus has threatened to shut off the flow of Russian gas to Europe within hours in a dispute over money.
The Minsk gas compressor station outside the capital
The Minsk gas compressor station outside the Belarussian capital
A European Union official has called the row an "attack" on the whole of the EU after Belarus told Russia it has until the morning to pay up $260m (?174m).
The latest development in the row sees Belarus claiming to have paid its debts to Russia's Gazprom, and in turn demanding Gazprom pay transit fees for allowing its supplies to Europe to cross its territory.
The dispute has already claimed its first European victim when Lithuania said it had suffered a 40% reduction in supplies that had come via Belarus.
This came after Russia cut gas supplies to Belarus by nearly two thirds.
In Minsk, deputy prime minister Vladimir Semashko said his country had transferred $187m (?125m) to Gazprom, and he called for the company to pay $260m (?174m) to Belarussian firm Beltransgaz for the transit fees.
Mr Semashko said if this was not done by 10am local time (8am UK time) then "we will be forced to shut down hydrocarbon transit through Belarussian territory".
Gazprom has not confirmed that Belarus has paid its debt. The firm's spokesman Sergei Kupriyanov said: "We will confirm when we receive the money."
Gazprom has not confirmed that Belarus has paid its debt
The dispute centres on Belarus' refusal to accept a hike in the price it pays for Russian gas.
This is from the $150 (?100) per 1,000 cubic metres it paid on average last year to $169.20 (?113) in the first quarter of this year and $184.80 (?123) in the second quarter.
The gas giant has said it would incrementally reduce gas supplies up to 85% of the normal volume if the debt is not settled in the coming days.
Following the cut, Belarus' president Alexander Lukashenko ordered a shutdown of Russian gas transit deliveries to Europe in retaliation.
This raised fears in the EU, whose members Lithuania, Germany and Poland depend on Russian gas piped through Belarus.
In a TV appearance for the third day running, the chief executive of Gazprom said the firm was cutting Belarus' supplies by 60% but added European customers should not worry.
Alexei Miller said: "Transit of Russian gas through the territory of Belarus is being implemented in the full amount and consumers of Russian gas do not experience any problems with it."