Ukraine has increased its gas reserves by more than 1 billion cubic meters and is exploring imports through the Trans-Balkan Corridor.

Between April 17 and May 24 2025, 1.06 billion cubic meters of natural gas were added to Ukraine’s underground storage, slightly surpassing last year’s amount during the same timeframe. Although the season started later this year, the injection rate is climbing, mainly due to higher imports. Daily imports currently exceed 20 million cubic meters – this is the highest level since February 2025, with Naftogaz of Ukraine as the primary importer.

The largest daily volumes are coming from Hungary – approximately 9.1 million cubic meters – and Poland, 5.9 million cubic meters. Since mid-May, Ukraine has also resumed gas imports from Slovakia. This route, while costlier, offers significantly greater capacity – up to 42 million cubic meters per day. Ukraine is also considering the Trans-Balkan Corridor as another import option, which remains underutilized due to high transportation costs.

Nonetheless, the gas transmission system operators in these nations have begun implementing the ROUT1 product with a 25% tariff reduction. If this proposal goes ahead, the Balkan route could become an appealing option for Ukrainian gas supplies.