Poland and Bulgaria have stopped receiving natural gas supplies from Russia on Wednesday, after the two countries refused to meet a demand by Moscow to pay in rubles.

The transcontinental country seized the supply to both countries in response to Western sanctions imposed on Moscow over the war in Ukraine.

This development was revealed in a statement on Wednesday by Russian state energy giant, Gazprom, CNN reports.

After they refused to meet a demand by Moscow to pay in rubles, rather than euros or dollars, the company said it had fully halted supplies to Polish gas company PGNiG and Bulgaria’s Bulgargaz.

The European Commission has reacted to the decision to halt supplies as an attempted “blackmail” emphasizing that it was coordinating a response among EU member states.

European Commission President Ursula von der Leyen in a statement said, “Europeans can trust that we stand united and in full solidarity with the member states impacted in the face of this new challenge. Europeans can count on our full support.”

According to the statement from PGNiG, starting Wednesday, it had been informed by Gazprom that deliveries through the Yamal pipeline would be suspended.

Bulgaria’s energy ministry also confirmed it in a statement that Gazprom would shut off gas supplies starting Wednesday.

The ministry said paying in rubles was unacceptable and posed “significant risks” to Bulgaria.