The governments of the two European countries said that Russian energy giant Gazprom informed them it was halting gas supplies.
The suspensions would be the first since Russian President Vladimir Putin said last month that “unfriendly” foreign buyers would have to pay the state-owned Gazprom in roubles instead of other currencies.
Europe imports large amounts of Russian natural gas to heat homes, generate electricity and fuel industry. The imports have continued despite the war in Ukraine.
Around 60% of imports are paid in euros, and the rest in dollars. Mr Putin’s demand was apparently intended to help bolster the Russian currency amid the war in Ukraine.
European leaders said they would not comply, arguing the requirement for them to purchase roubles and then pay Gazprom violated the terms of contracts and their sanctions against Russia.
“The Russian proposal for a two-step payment procedure is in violation with the current contract and bears considerable risks for Bulgaria, including to make payments without receiving any gas deliveries from Russia,” the Bulgarian government said.
Bulgaria said it was working with state gas companies to find alternative sources. The government said no restrictions on domestic gas consumption would be imposed for now even though the Balkan country of 6.5 million meets over 90% of its gas needs with Russian imports.
Poland’s state gas company, PGNiG, said it was notified by Gazprom that deliveries through the Yamal-Europe pipeline would stop on Wednesday.
Poland not only has refused to pay for natural gas in roubles, but the country has been a strong supporter of neighbouring Ukraine during the Russian invasion.
It is a transit point for weapons the United States and other Western nations have provided Ukraine.
The Polish government confirmed this week that it was sending tanks to Ukraine’s army. On Tuesday, it announced a sanctions list targeting 50 Russian oligarchs and companies, including Gazprom.
The Yamal pipeline carries natural gas from Russia to Poland and Germany, through Belarus. Poland has been receiving some nine billion cubic metres of Russian gas annually.
PGNiG said that Russia’s demand to be paid in roubles represented a breach of the Yamal contract.
Flow charts published on the website of the European Network of Transmission System Operators for Gas showed drastic drops of gas flows at entry points in Kondratki, a town in eastern Poland, and Vysokaye, which is in Belarus.
The Russian news agency Tass cited Gazprom as saying that Poland must pay for its gas supplies under a new procedure.
Polish Climate Minister Anna Moskwa stressed that Poland was prepared for such a situation after working for years to reduce its reliance on Russian energy sources.
She said the country has been effectively independent when it comes to Russian gas for some time.
“There will be no shortage of gas in Polish homes,” Ms Moskwa tweeted.
The minister repeated that message at a news conference, saying: “Appropriate diversification strategies that we have introduced allow us to feel on the safe side in this situation.”
Poland has been working since the 1990s to wean itself off of Russian energy and was already on track to end its reliance on Russian gas this year. It recently moved to stop imports of Russian coal.
The government in Warsaw has urged other European countries to lessen their dependence on Russian energy sources.