Russia cuts off a major supply of natural gas to Poland and Bulgaria.

But with winter now over, warming temperatures should help lessen the blow in both, at least in coming months. Unlike some of its neighbors, 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 V. 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 three millions refugees have fled across the Polish border.

Bulgaria is traditionally more pro-Russian than most other European countries, particularly Poland, but it nonetheless endorsed European Union 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 favor countries that don’t criticize it with reliable supplies of energy. During a visit in Moscow from Hungary’s Kremlin-friendly leader, Viktor Orban, shortly before Russia invaded Ukraine, Mr. Putin offered assurances that Hungary, unlike other European countries, did not have to worry about running short of natural gas.