Slovakia and Hungary on Wednesday condemned European Commission plans to phase out Russian gas and other energy imports, deepening a rift with Brussels over relations with Moscow.

The EU executive had said on Tuesday it would propose legal measures next month to phase out EU imports of Russian gas and liquefied natural gas by the end of 2027.

The plans also touch on oil and include trade measures targeting Russian enriched uranium for nuclear power that would amount to a tax or levy on imports.

The move is part of the EU's pledge to end its decades-old energy relations with former top gas supplier Russia after its full-scale invasion of Ukraine in February 2022.

Slovak Prime Minister Robert Fico said he respected attempts to reduce energy dependence on third countries but the Commission's proposals would harm the EU, raising prices in the bloc and damaging its competitiveness.

"This is simply economic suicide to go to the point where neither gas, nor nuclear, nor oil, everything must end just because some new Iron Curtain is being built between the Western world and perhaps Russia and other countries," Fico said.

Slovakia would work for changes in the legislative process, he said.

Slovak gas importer SPP said in a statement that the measures could "have a significantly negative impact on the competitiveness of the business sector of the European Union."

Hungarian Foreign Minister Peter Szijjarto also said on Wednesday that the EU's plan on Russian energy was "unacceptable" and that Budapest would "take the strongest possible steps" against the scheme, without giving details.

"We will fight and challenge this decision," Szijjarto said.

The Commission's legal proposals due in June will require approval from the European Parliament and a qualified majority of member states - meaning one or two countries cannot block the plans.

Slovakia and Hungary receive Russian gas and oil supplies and have argued with Ukraine over its decision at the end of last year to halt gas flows from the east through its territory.

Around 19% of Europe's gas still comes from Russia via the TurkStream pipeline and LNG shipments, down from roughly 45% before 2022.

Slovakia's ministry says 10 of the bloc's 27 members imported Russian gas last year.

The EU has imposed sanctions on most Russian oil imports but not on gas due to opposition from Slovakia and Hungary, which receive Russian pipeline supplies and maintain closer ties with Moscow.