A Romanian F-16 fighter jet pilot shot down a Russian drone over the Black Sea, the Defense Ministry said on Sunday, the latest in a series of breaches of the NATO member's airspace that President Nicusor Dan called "inadmissible and intolerable."

Romania shares a 650-kilometer (400-mile) land border with Ukraine and Russian drones have repeatedly violated its airspace during the more than four-year Ukraine war. Moscow is now stepping up attacks on Ukrainian ports across the Danube River.

Romania had not destroyed any of the drones until Friday when a Romanian pilot was able to safely bring one down in an uninhabited area. It has now shot down three drones in as many days.

"It is inadmissible and intolerable for the Russian Federation to continue violating Romania's airspace, which is, at the same time, NATO airspace and European Union airspace," Dan wrote on X on Sunday.

"Such actions are unacceptable, and we treat them with the utmost seriousness, alongside our allies," he said.