INFURIATED by the West’s supply of arms and other support to help Ukraine resist invading Russian troops, Moscow on Tuesday (Apr 26) took the fight to Europe’s economy, telling Poland and Bulgaria that it was halting supplies of natural gas, on which both countries and Europe in general are heavily dependent.

A decision by Russia’s energy behemoth Gazprom to cut off gas supplies to 2 countries that are both members of Nato and the European Union marks the first time that Moscow has directly and openly targeted Europe with its energy weapon. The move upends assurances by Moscow since the Soviet era that, no matter what the political climate, Russia could be counted on as a reliable supplier of natural gas.

European countries have suffered sporadic interruptions in Russian gas supplies in the past, but these were largely the result of squabbles between Russia and Ukraine over what Gazprom claimed were unpaid bills and the theft of gas destined for Europe through a pipeline that crosses Ukrainian territory.

On Tuesday, however, Poland’s main importer of Russian gas, the state-owned company PGNiG, said that Gazprom had announced the “complete suspension” of deliveries through the Yamal pipeline, which stretches from northern Siberia to Poland and Germany through Belarus.

PGNiG said that it had received a letter from Gazprom informing it that all deliveries through the Yamal pipeline were being halted.

Bulgaria’s energy ministry said later Tuesday that it, too, had been told by Gazprom that its own gas supplies from Russia, which flow through the Ukrainian pipeline, would stop.

Germany also receives some gas through the Yamal pipeline but most of what it needs from Russia flows through Nord Stream, a separate pipeline under the Baltic Sea that appeared to be still operating normally Tuesday.

Poland, the biggest economy in Europe’s formerly communist east, gets more than 45 per cent of its gas from Russia, while Bulgaria gets around 90 per cent.

Since Russian invaded Ukraine on Feb 24, both countries have announced plans to wean themselves off Russian energy, but the abrupt halt announced Tuesday could seriously wound the ability of both countries to heat homes and run businesses.

But with winter now over, warming temperatures should help lessen the blow in both, at least in coming months. Unlike some of its neighbours, Poland burns coal, not gas, for most of its electricity, so it is less vulnerable on that front.

Poland’s climate minister, Anna Moskwa, played down the impact of Russia’s decision, insisting at a news conference in Warsaw on Tuesday that “we are ready to be fully cut off” from Russian gas. Bulgaria’s energy ministry, in a statement, assured consumers that “currently, no restrictions are required on gas consumption in Bulgaria”.

Russia’s decision nonetheless marked a significant ratcheting up of tensions with the European Union, which, since Russia invaded Ukraine, has joined the United States in imposing increasingly stringent economic sanctions, badly damaging the Russian economy.

Both Poland and Bulgaria, along with other European countries except for Hungary, rejected a demand by President Vladimir Putin of Russia that energy purchases be paid for in rubles to help prop up his currency, though the contracts for foreign sales generally require payment in dollars.

Russia has been particularly angry at Poland because of Warsaw’s robust support for Ukraine, which has received many of its Nato-supplied arms through Polish territory and from which nearly 3 million refugees have fled across the Polish border.

Bulgaria is traditionally more pro-Russian than most other European countries, particularly Poland, but it nonetheless endorsed EU sanctions against Russia — unlike Serbia, a Russia-friendly country that is not a member of the European bloc. Bulgaria’s new coalition government has been convulsed by tension over whether to send arms to Ukraine.

Russia has made clear for months that it will favour countries that don’t criticise it with reliable supplies of energy. During a visit in Moscow from Hungary’s Kremlin-friendly leader, Viktor Orban, shortly before Russia invaded Ukraine, Putin offered assurances that Hungary, unlike other European countries, did not have to worry about running short of natural gas.

In a sarcastic message on social media last month, Dmitry Medvedev, the deputy head of the Kremlin’s security council and a longtime ally of Putin, sneered at European leaders as fools for taking measures against Russia that he said would ensure they don’t have enough energy.

“Excellent. The wise decisions of European politicians,” Medvedev wrote.

The bloc has vowed to cut off its large imports of Russian oil and coal over a period of months, as it searches for replacements and adjusts to higher fuel costs. But Europe is even more dependent on Russian gas, and ending those imports would be more economically damaging; EU ministers have said they will reduce the flow from Russia, but not shut it off until 2030. NYTIMES