BRUSSELS (Reuters) -The European Union will publish plans on Tuesday to ban new Russian gas deals by the end of this year, and phase out existing contracts with Moscow by the end of 2027, three EU officials told Reuters.

The bloc had set a non-binding aim to end Russian fossil fuel imports by 2027 after Moscow's full-scale invasion of Ukraine in 2022.

The EU Commission's plan includes a commitment to propose in June a ban on new Russian gas import deals and spot contracts by the end of 2025, the officials told Reuters.

It will also make a legal proposal to ban Russian gas and liquefied natural gas imports under existing contracts by the end of 2027, said the officials, who wished to remain anonymous to discuss the confidential plans, which could still be changed before they are published.

The legal proposals would need approval from the European Parliament and a reinforced majority of EU countries.

The EU has imposed sanctions on Russian coal and seaborne oil shipments, but not on gas due to opposition from Slovakia and Hungary, which receive Russian pipeline supplies and say switching to other suppliers would hike energy prices. Sanctions require unanimous approval from all 27 EU countries.

Around 19% of Europe's gas still comes from Russia, via the TurkStream pipeline and liquefied natural gas shipments.

That's far below the roughly 40% Russia supplied before 2022. But European buyers still have "take-or-pay" contracts with Gazprom which require those that refuse gas deliveries to pay for much of the contracted volumes.

The Commission has been assessing legal options to allow European companies to break existing Russian gas contracts without facing financial penalties.

The EU officials did not specify how Brussels intends to do this. Lawyers have said it would be difficult to invoke "force majeure" to quit these deals, and that buyers could face penalties or arbitration for doing so.

The proposals were first reported by Bloomberg News.

Uncontracted "spot" purchases made up around 31% of the Russian LNG Europe bought last year, Rystad Energy data show.

As it attempts to cut decades-old energy ties with Russia, the European Commission has signalled willingness to buy more U.S. LNG, a step President Donald Trump has demanded from Europe as a way of shrinking its trade surplus with the United States.

The Commission is also concerned about energy prices, and has said any measures to restrict Russian energy imports must hurt Moscow more than the EU, and take into account the impact on fuel costs.

The U.S. is pushing Russia for a peace deal with Ukraine, which, if reached, may reopen the door for Russian energy and ease sanctions.

The European Commission had originally planned to publish its roadmap in March, but delayed it in part due to uncertainty around these developments.