The future of gas transit through Ukraine is at a turning point. If a last-minute deal isn’t struck by Wednesday, billions of cubic meters in gas flows could come to a halt.

Ukraine is under mounting pressure from Slovak Prime Minister Robert Fico and a group of central European companies to keep gas moving from its eastern border with Russia to European Union buyers once a transit agreement expires on Tuesday.

Almost three years after the full-scale Russian invasion of Ukraine, Budapest and Bratislava still rely on cheap gas from Gazprom, undermining the European Union push to cut reliance on Russian energy.