Slovakia's coalition government will discuss retaliatory measures to take against Ukraine after it halted the flow of Russian gas through its territory to Slovakia, Slovak Prime Minister Robert Fico said on Thursday.

Despite EU efforts to reduce dependence on Russian fossil fuels, Slovakia remains reliant on Russian gas under a long-term contract with Russia's state-owned energy giant Gazprom. Switching to alternative supply routes could cost Slovakia an additional €220 million ($229 million) in transit fees.

Ukrainian Energy Minister German Galushchenko also says Kyiv can buy electricity from Romania and Poland if it loses supplies from Bratislava.

President Volodymyr Zelensky condemned Slovakia's Prime Minister Robert Fico recent threats to cut off Ukraine's emergency power supply in the winter, saying that it appears he has been acting on Russian President Vladimir Putin's orders.

Poland is prepared to step up electricity exports to Ukraine if Slovakia’s Prime Minister Robert Fico follows through on his threat to cut off back-up power supplies to the war-torn country, a senior official said on Sunday.

Slovakia will consider reciprocal measures against Ukraine such as halting back-up electricity supplies after Jan. 1 if Kyiv, as expected, stops the transit of Russian gas to Slovakia, Prime Minister Robert Fico said on Friday.

On New Year's Day, the transfer of Russian gas through Ukraine has ended after Kyiv had refused to extend a long-running contract due to Russia's war against the country.

Russia halts gas transit to the EU via Ukraine after the transit deal expires, sparking energy concerns and diplomatic tensions. Slovakia threatens electricity cuts to Ukraine, further escalating the dispute.