Mines began floating in the Black Sea after Russia invaded Ukraine on Feb. 24, and Romanian, Bulgarian and Turkish military diving teams have been defusing those drifting in their waters.
The ministry said the navy was alerted by a Turkish cargo ship about a mine drifting some 2.5 nautical miles (4.6 km) north of the Romanian Black Sea port of Constanta.
The Black Sea is crucial for shipment of grain, oil and oil products. Its waters are shared by Bulgaria, Romania, Georgia and Turkey, as well as Ukraine and Russia.
The mine defused on Saturday was the fourth handled by the Romanian military since March. Since the war started, Turkey, Romania, Bulgaria and Ukraine have destroyed roughly 40 mines in western waters of the Black Sea.