Russia has been accused of using gas as blackmail after suspending supplies to Poland and Bulgaria.
Gas deliveries through the Yamal-Europe pipeline have come to a halt, data from the European Union network of gas transmission operators shows.
Gazprom, the Russian gas giant, told the Polish state gas company, PGNiG, that gas would stop flowing.
It also told Bulgargaz, the Bulgarian state gas company, that it will halt gas supplies on Wednesday, according to the country’s energy ministry.
"Payments for gas supplied from April 1 must be made in roubles using the new payments details, about which the
counterparties were informed in a timely manner," Gazprom said.
It comes after Russian President Vladimir Putin said last month that "unfriendly" foreign buyers would have to pay the state-owned Gazprom in the Russian currency instead of dollars and euros, which the international community has refused to do.
Anna Moskwa, Poland’s climate minister, insisted the country 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.
Poland said it did not need to draw on reserves and its gas storage was 76% full.
"There will be no shortage of gas in Polish homes," Ms Moskwa tweeted, before repeating that message at a news conference.
"Appropriate diversification strategies that we have introduced allow us to feel on the safe side in this situation," she said.
Bulgaria has paid for Russian gas deliveries for April and halting gas supplies would be a breach of its current contract with Gazprom, energy minister Alexander Nikolov told reporters.
He said Bulgaria would observe the European Commission’s stance urging countries not to pay in roubles for Russian gas.
European Commission President Ursula von der Leyen said the EU was working on a coordinated response to the escalation by Moscow.
"The announcement by Gazprom that it is unilaterally stopping delivery of gas to customers in Europe is yet another attempt by Russia to use gas as an instrument of blackmail," Ms von der Leyen said in a statement.
"This is unjustified and unacceptable. And it shows once again the unreliability of Russia as a gas supplier," she said.
British Deputy Prime Minister Dominic Raab has said Russia’s decision will add to its status as an economic and political pariah.
"It (halting gas supply) will have a … very damaging effect on Russia as well because it is becoming further and
further, more and more, not just a political pariah, but an economic pariah," Mr Raab told Sky News.
Andriy Yermak, chief of staff to Ukraine’s President Volodymyr Zelenskyy, said Russia was "beginning the gas
blackmail of Europe".
"Russia is trying to shatter the unity of our allies," Mr Yermak said.
Germany will still be served by the undersea Nordstream pipeline.
Hungary and Austria also said gas supplies were normal.
Bulgaria has said it was working with state gas companies to find alternative sources.
"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.
It added that no restrictions on domestic gas consumption would be imposed for now, despite the Balkan country of 6.5 million meeting over 90% of its gas needs with Russian imports.
The Yamal pipeline connects Russian natural gas fields in the Yamal Peninsula and Western Siberia with Poland and Germany, through Belarus, and is around 2,552 miles long.
Poland has been receiving around nine billion cubic metres of Russian gas every year.
Europe imports large quantities of natural gas from Russia to heat homes, generate electricity and fuel industry – and the imports have continued despite the war in Ukraine.
Some 60% of gas imports are paid in euros, and the rest in dollars.
European leaders responded to Mr Putin’s demands to pay in roubles by saying they would not comply – arguing the requirement violated the terms of contracts and their sanctions against Russia.
PGNiG has also said that Russia’s demand to be paid in roubles is a breach of the Yamal contract.
Elsewhere, Denmark’s Orsted repeated on Tuesday that it has "no intention" of paying Russia in roubles for gas.
Ukrainian refugees have flooded into Poland since the war broke out – with the country being a strong supporter of its neighbour.
It is also a transit point for weapons coming from the US and other western nations for Ukraine.
© Sky News 2022