SOFIA - A joint naval exercise of US, Bulgarian and Romanian naval forces in the Black Sea has started, the Bulgarian navy said on Wednesday.

The USS Truxtun, a US guided-missile destroyer with about 300 crew and part of the US Sixth Fleet headquartered in Italy, joined the manoeuvres with Bulgarian naval frigate Drazki and three Romanian vessels in the Black Sea.

The drills started across the water from the Crimean Peninsula where Russian military groups have seized control from Ukrainian authorities.

"This time the exercise has begun as planned," Lieutenant-Colonel Dimitar Titev said. The drills were delayed by one day on Tuesday due to bad weather.

Bulgarian Defence Minister Angel Naydenov said that the Ukrainian ambassador to Sofia, Mikola Baltaji informed him that a joint BLACKSEAFOR naval exercise, that was to be led by Ukraine between March 28 and April 15, was cancelled.