BRUSSELS — Hungary and Slovakia will sue the European Union over its plan to ban all imports of Russian gas as soon as the law officially comes into force, the countries’ foreign ministers announced today.

Hungarian Foreign Minister Péter Szijjártó wrote on X Monday that the country would use “every legal means” to have the ban annulled, adding the ban went “against our national interest and would significantly increase energy costs for Hungarian families.”

EU lawmakers and leaders agreed in December to end all purchases of gas from Russian exporters by the end of 2027, with a similar ban on crude likely to come later this year.

Leaders rubber-stamped the law on Monday, but Hungary and Slovakia — which are highly dependent on Russian fossil fuels — voted against the measure, arguing that it would send energy prices skyrocketing.

Hungary said it would begin proceedings against the EU as soon as the law is formally adopted, which is likely to be in early February. Szijjártó has repeatedly threatened to sue the EU but this is the first time he has laid out a specific timeframe.

He criticized the EU’s use of a “legal trick” to pass the law by presenting it as a trade measure rather than a sanction, which would have required unanimity.

Slovakia will also sue the bloc, Foreign Minister Juraj Blanár said in a statement, without giving a specific date.

“We cannot accept solutions that fail to reflect the real capacities and specific circumstances of individual countries,” he said.