Bulgaria is intensifying efforts to enhance regional energy security through the development of strategic infrastructure aimed at reducing dependence on Russian gas. A central initiative in this process is the Vertical Gas Corridor, designed to transport liquefied natural gas (LNG) regasified at Greek ports to Central and Eastern Europe, including Ukraine. Greece’s Revitusa LNG terminal, with a capacity of 7.5 billion cubic meters per year, has been supplying gas to Bulgaria since 2019. Bulgarian officials view this corridor as a vital alternative to Russian supplies for European markets.

Energy Minister Zhivko Stankov recently announced that construction on the Bulgarian segment of the corridor would begin within weeks. The completed system will enable the transit of up to 10 billion cubic meters of gas annually to countries such as Romania, Hungary, Slovakia, Moldova, and Ukraine. Bulgaria has already committed nearly 0 million to its part of the project, which is expected to be finalized by the end of 2026. Sofia is also engaged in negotiations for long-term LNG supply contracts to ensure the corridor operates at full capacity.

Talks are currently underway with Hungary, Moldova, and Ukraine on organizing joint LNG procurement tenders. One of the top priorities for Bulgaria and its partners is to secure stable, long-term supply agreements with fixed pricing, which will bolster energy reliability across the region.

Though the Vertical Gas Corridor was formally announced in 2023, its origins trace back to 2016, when it was proposed by Greece, Bulgaria, Romania, Hungary, and Austria. The project will utilize the Trans-Balkan gas pipeline – a system that traditionally carried Russian gas from Ukraine to Greece – by reversing its flow. Now, gas will travel from Turkey toward Ukraine, with some parts of the infrastructure already repurposed to carry supplies from the TurkStream pipeline.

At the same time, Bulgaria and Turkey are holding negotiations to expand their cross-border gas transit infrastructure. While Russia anticipates that this expansion could increase its exports, the improved capacity will also enable more imports from Azerbaijan and Central Asia. The current transit capacity between the two countries is 3.5 billion cubic meters annually, and plans are in place to double this without building a new pipeline—just by upgrading the existing network.

Presently, the only functioning Russian gas route to Europe runs through Bulgaria via the TurkStream extension. Discussions between Sofia and Ankara on increasing gas transit capacity are expected to continue until early May. Turkey has voiced its full support for the Vertical Gas Corridor and its broader vision of becoming a key energy hub for the continent.

Industry observers point out that Bulgaria remains a bottleneck in Europe’s gas transmission system. To address this, Sofia began constructing two interconnectors last June: one that duplicates the Kulata-Kresna segment to expand the Kulata-Sidirokastro route with Greece, and another at Rupcha-Vetrino to boost capacity toward Romania via the Negru Voda-Kardam interconnector. These "duplications" will build parallel pipelines to increase throughput.

The Vertical Gas Corridor will also facilitate LNG imports from a range of suppliers, including the United States, Egypt, Azerbaijan, and other Caspian states. In particular, Azerbaijan’s Trans Adriatic Pipeline (TAP), part of the Southern Gas Corridor, currently supplies 10 billion cubic meters per year and is on track to double capacity to 20 billion by 2027. Bulgaria's gas connectivity was further strengthened in 2022 with the completion of the Greece-Bulgaria Interconnector (IGB), linking Komotini and Stara Zagora. The 182.6 km pipeline can carry 3 billion cubic meters annually, expandable to 5 billion.

Turkey’s long-term vision for energy includes consolidating gas supplies from over 30 countries into a unified brand, Turkish Blend, to create a competitive market. Turkish Energy Minister Alparslan Bayraktar emphasized the need for multiple energy sources and competition among suppliers to establish Ankara as a continental gas hub. Turkey is also expanding two floating storage and regasification units (FSRUs) to support this ambition. The upgraded pipeline capacity through Bulgaria will enable gas delivery to Romania, Hungary, Slovakia, North Macedonia, and Serbia.

The Vertical Gas Corridor and Turkey’s gas hub initiative reflect significant shifts in Europe’s energy landscape. As the continent works to diversify its energy mix and strengthen internal connectivity, Southeastern Europe is emerging as a critical player. The coordinated efforts of Bulgaria, Turkey, Greece, and Azerbaijan are transforming regional energy cooperation into a cornerstone of Europe’s broader energy strategy.