Russia’s once-dominant gas supply to Europe via Ukraine, which flowed for decades, is set to end on New Year’s Day with the collapse of a contract between the two warring countries that paid out billions to Moscow in gas revenue and to Kyiv in transit fees.

The shutdown of Russia’s oldest gas route to Europe ends a decade of fraught relations sparked by Russia’s seizure of Crimea in 2014.

The European Union redoubled its efforts to reduce its dependence on Russian energy after the outbreak of the war in Ukraine in 2022 by seeking alternative sources.