Finnish Prime Minister Sanna Marin on Tuesday appealed for EU unity in the face of Russian "blackmail" over energy supplies, and for more sanctions on Moscow.
Her call, made to the European Parliament sitting in Strasbourg, France, came a day before EU chief Ursula von der Leyen was to deliver her annual "State of the European Union" address to be dominated by the impact of the war in Ukraine on Europe.
Accusing Russia of weaponising energy by severely reducing gas supplies, Marin told MEPs: "Blackmailing our societies through energy supply is a way for Russia to crumble and destroy Europeans' support to Ukraine and to destroy our unity."
Russian President Vladimir Putin "must not be allowed to succeed in this," she said, urging EU "unity, determination and courage" to get through the coming winter.
Von der Leyen's European Commission, she said, must come up with "new, bold solutions" to bring down a sky-high surge in electricity prices for European households and businesses.
Von der Leyen is expected to set out a commission proposal to do that in her Wednesday speech, though EU countries are split over what measures to take and what scope they should have.
"Russia is destroying its own economy and its own future" by forcing Europe to end its dependency on Russian fossil fuels, Marin said.
But the consequences of that were being felt in Europe and further afield.
"We are now paying a high price for dependency on Russian energy. The war and the price of energy also threaten to bring a food crisis to the world," she said.
Finland is in the process of joining NATO, along with Sweden, spurred by Russia's invasion of Ukraine.
Marin said the EU needs to hit Russia with more sanctions so it feels the cost from its war, and said recent agreement in the bloc to do away with a visa facilitation agreement for Russians did not go far enough.
"The sanctions must be reflected in the everyday lives of ordinary Russians.... We must limit the issuing of visas very strongly," she said
