By Courtney Weaver in Moscow, Joshua Chaffin in Brussels and Roman Olearchyk in Kiev
Belarus threatened to shut off all Russian oil and gas flows to Europe from Thursday as Lithuania reported the first disruption of gas flows to Europe on the third day of a dispute between between Belarus and Gazprom, the Russian gas monopoly.
Vladimir Semashko, Belarus's first deputy prime minister, announced that the country had repaid Gazprom the $187m (?153m, ?125m) it owed for gas deliveries for January through April but was still waiting to receive the $260m which it says the Russian group owes in transit fees.
"Now we have the absolute right to demand Gazprom to repay [its debt] by 10:00 on June 24?.?.?.?If that's not done we will need to block the transit of hydrocarbons," he said.
Gazprom said it had not yet received the money from Belarus.
Speaking in Brussels on Wednesday, Gunther Oettinger, EU energy commissioner, told Belarus to stop involving Europe in its dispute with Russia.
"The government of Belarus wants to integrate Europe in their problems, and that is not OK," he said.
Lietuvos dujos, the Lithuanian gas utility, told reporters in Vilnius on Wednesday that it was experiencing 40 per cent cuts in gas flows to Lithuania and Russia's Kaliningrad region a day after Alexander Lukashenko, president of Belarus, said the country had cut gas transit to Europe.
Lietuvos dujos said it had seen flows drop from noon but did not expect to limit gas supplies to its customers.
However, Mr Oettinger told reporters that the reason for the cut in gas supplies to Lithuania was unclear.
The disruption to Lithuania echoes previous gas conflicts between Russia and its former Soviet neighbour, Ukraine, which disrupted gas flows to Europe for up to two weeks at a time.
Lithuania remains heavily dependent on Russian fuel supplies two decades after breaking from the Soviet Union and the situation has worsened since the closure of the country's Ignalina nuclear plant last year.
The European Commission has granted billions of euros to build new pipeline interconnections between member states, which would allow them to share supplies more easily, while Ukraine has simultaneously been promoting the dispute as a reason for Europe to drop plans for alternative pipelines that would bypass Ukraine altogether.
Serhiy Lyovochkin, chief of staff to Viktor Yanukovich, Ukraine's Moscow-friendly president, said his country was ready to pump more Russian gas to Europe to compensate for shortages caused by the dispute between Minsk and Moscow but said Ukraine was not seeking to "win" from the gas spat by taking sides in the dispute.
Ukraine's aim, he said, was to "demonstrate the reliability of our gas transit system."
The European Commission said it did not expect to see major disruptions in this dispute as gas shipped through Belarus accounts for just 6.25 per cent of EU consumption - a fraction of that which reaches Europe via Ukraine.
Gunther Oettinger, the energy commissioner, spoke on Monday with both Sergei Shmatko, the Russian energy minister, and Mr Semashko,. "He said that Europe must not be taken hostage in this dispute - that this is an issue between Russia and Belarus," his spokesperson said.
Additional reporting by Andrew Ward in Stockholm