Ukraine just stopped Russian gas flows to Europe. Here's who's most at risk

Ukraine halted the flow of Russian gas to several European countries on New Year's Day, bringing an end to Moscow's decades-long dominance over Europe's energy markets.

Russia's state-owned energy giant Gazprom confirmed gas exports to Europe via Ukraine stopped at around 8 a.m. local time (5 a.m. London time) on Wednesday.

The widely expected move marks the end of a five-year transit agreement between Russia and Ukraine, with neither side willing to strike a new deal amid the ongoing war.

Ukrainian President Volodymyr Zelenskyy said last month that Kyiv was not prepared to prolong the transit of Russian gas, adding, "We will not give the possibility of additional billions to be earned on our blood."

Russia, which has transported gas to Europe via Ukrainian pipelines since 1991, says European Union countries will suffer the most from the supply shift. Moscow can still send gas via the TurkStream pipeline, which links Russia with Hungary, Serbia and Turkey.

Ukraine will lose up to $1 billion a year in transit fees from Russia due to the stoppage, according to Reuters, while Gazprom is poised to lose close to $5 billion in gas sales.

The European Commission, the EU's executive arm, said it had been working with EU member states most impacted by the end of the gas transit agreement to ensure the entire 27-nation bloc was prepared for such a scenario.

Slovakia, Austria and Moldova are among the countries most at risk from the stoppage. They were the European countries most dependent on transit volumes of Russian gas in 2023, according to Rystad Energy, with Slovakia importing roughly 3.2 billion cubic meters that year, Austria receiving 5.7 billion cubic meters and Moldova getting 2 billion cubic meters.

Austria has insisted it is