NATO forces and the Ukrainian army have launched joint military exercises in the Black Sea near the Crimean Peninsula that rejoined Russia last year.

The naval drills, code-named Sea Breeze 2015, began on Monday in Ukraine's Odessa and Nikolaevsk regions with the participation of 2,500 troops and some 150 military vehicles.

Kiev has deployed 1,000 forces, nine warships and eight aircraft for the maneuver, in which 1,000 US marines as well as five warships, two submarines and six aircraft are also involved.

The remaining 500 soldiers, six warships, three submarines and six aircraft belong to Bulgaria, Germany, Greece, Italy, Romania, Turkey, the UK and the non-NATO countries of Moldova and Sweden.

"The maneuvers are to enhance confidence and security in the region, and improve interoperability between the naval force of Ukraine and NATO and partner countries," the Ukrainian Defense Ministry said in a statement.

The war games, scheduled to run until September 12, have been conducted annually in Ukraine since 1997 except for the years of 2006, 2007 and 2009.

Moscow has repeatedly condemned the western military alliance's exercises and military buildup towards its borders.

The Moscow-West relations sharply cooled after Crimea’s reunification with Russia following a referendum in March 2014. Relations were strained further after Ukraine launched military operations in April 2014 to silence pro-Russia protests in the country’s mainly Russian-speaking regions of Donetsk and Luhansk in eastern Ukraine.

Kiev and its Western allies accuse the Kremlin of meddling in Ukraine’s internal affairs and backing pro-Russia forces in eastern Ukraine. Russia has resolutely denied the claims.

The UN figures show some 7,000 people have so far been killed in the conflict in Ukraine’s east.