Romania's Defense Ministry says some 1,600 sailors are taking part in navy training exercises in the Black Sea amid tensions in neighboring Ukraine.

The ministry said in a statement that Romania's "Vector 2014" exercises are part of a regular and long-planned naval drill. It began Monday and is to run through Friday in Romanian and international waters of the Black Sea.

The exercises come amid heightened tensions in Ukraine after Russia annexed Crimea and unrest has spread to Ukraine's port city of Odessa.

Romania, a staunch U.S. ally and NATO member, is some 300 kilometers (190 miles) from Odessa.

The U.S. Navy destroyer USS Donald Cook left the Black Sea last month after two weeks of joint military maneuvers and the U.S. frigate USS Taylor is still in the region.