Southeastern Europe is experiencing a significant transformation in its energy landscape, driven by a strategic shift in U.S. energy policy aimed at redefining regional energy flows and infrastructure. This evolution, prompted by the decline of Russian gas dominance, has led to the region being positioned as a vital transit and balancing hub that connects Mediterranean gas supplies with Central European demand and Ukrainian storage capabilities.
The U.S. “energy dominance” initiative, formalized with the establishment of the National Energy Dominance Council in 2025, serves as the foundation for this transition. This doctrine emphasizes not only domestic energy production but also integrates energy exports into a broader geopolitical strategy encompassing trade and defense. Southeastern Europe has become a focal point for operationalizing this approach through investments in liquefied natural gas (LNG), crude oil, and nuclear technology.
A pivotal moment occurred in early 2026 when the European Union committed to purchasing $750 billion of U.S. LNG, crude oil, and nuclear fuel by 2028, marking an increase from $90 billion in 2024. This agreement ensures long-term demand for U.S. energy exports while necessitating extensive infrastructure development across Europe to manage these increased volumes. For Southeastern Europe, which has historically faced infrastructure limitations, this agreement presents both opportunities for growth and challenges related to capacity constraints.
Trade flows already reflect these changes, with U.S. LNG exports to Europe rising from 64.9 bcm in 2024 to 106.6 bcm in 2025. However, Southeastern Europe remains underrepresented in these imports, receiving only 4.37 bcm in 2025. The region’s potential for growth is evident but highlights existing limitations that need addressing.
Key entry points for LNG expansion are located along the Mediterranean coast, particularly at Croatia’s Krk terminal and Greece’s Revithoussa and Alexandroupolis facilities, which collectively offer around 18.6 bcm of regasification capacity. These facilities are evolving from isolated national assets into integral components of a broader corridor system designed to facilitate gas transport northward into Hungary and Slovakia, ultimately connecting to Ukraine.
The market is also witnessing a transition from short-term spot purchases to long-term contracts, exemplified by agreements between U.S. exporters like Venture Global and regional buyers that establish multi-decade supply frameworks essential for securing financing for large-scale infrastructure projects. This shift is particularly impactful in Southeastern Europe where financial constraints have historically hindered project execution.
Infrastructure developments are increasingly characterized by corridor-oriented planning rather than isolated national initiatives. The Vertical Gas Corridor connects Greece through Bulgaria and Romania into Central Europe while being enhanced by the Ionian-Adriatic Pipeline—a 516-kilometre project with a capacity of 5 bcm linking Croatia to Albania via Bosnia and Herzegovina and Montenegro—creating a coherent south-north transmission network that integrates LNG imports with inland demand centers.
The strategic importance of this system goes beyond transportation; Ukraine’s vast underground gas storage facilities have emerged as crucial balancing mechanisms within this evolving market structure. By connecting Mediterranean LNG supplies to Ukrainian storage capabilities, the region is progressing toward a more functional gas market characterized by improved liquidity and seasonal flexibility.
The oil sector is simultaneously undergoing significant changes as well; U.S. crude exports to Southeastern Europe reached approximately 11.5–13 million tonnes in 2025, primarily entering through Greece. Refineries in Hungary, Slovakia, and Serbia are increasingly shifting from traditional Russian supply routes via the Druzhba pipeline to seaborne imports through the Adriatic Sea due to the pipeline’s shutdown in early 2026.
Despite these advancements, challenges persist within the region’s energy landscape. Total gas consumption across Southeastern Europe stands at around 30 bcm annually, with consumption distribution notably uneven among countries such as Greece, Romania, and Serbia compared to others like Montenegro and Kosovo that lack adequate infrastructure. Romania leads regional production at 9.2 bcm, followed by smaller contributions from Croatia and Serbia.
Nuclear energy is gaining traction as a complementary component of this evolving energy framework; U.S.-based technology providers advocate for Small Modular Reactors (SMRs) as scalable solutions for enhanced baseload generation while supporting decarbonization efforts across the region. Romania is spearheading this initiative with plans for a 77 MW SMR module targeted for commissioning by 2033, while other nations including Croatia, Greece, and Serbia explore similar pathways.
This transformation aligns with broader initiatives such as the Three Seas Initiative which promotes north-south connectivity across various sectors including energy and transportation—strengthening the corridor model that positions Southeastern Europe as an essential link between Mediterranean supply sources and Central European markets.
The ongoing recalibration of energy sovereignty reflects a shift towards resilience characterized by diversified supply chains and integrated infrastructures rather than mere self-sufficiency. For the United States, enhancing its role as an energy exporter serves both commercial interests and geopolitical objectives; meanwhile, Europe’s challenge lies in establishing stable markets capable of accommodating increased external supply effectively.
Southeastern Europe’s integration into a transatlantic energy framework anchored by U.S. supply marks a significant shift from being merely an endpoint consumer to becoming an intermediary conduit within global energy networks—signifying its growing strategic relevance on the European energy map amidst ongoing geopolitical dynamics.
