Ukraine and the United States will start a military exercise involving more than 30 countries in the Black Sea and southern Ukraine, despite Russian calls to cancel the drills, writes Reuters.

Sea Breeze 2021 follows a rise in tensions between NATO and Moscow, which said last week it had fired warning shots and dropped bombs in the path of a British warship to chase it out of Black Sea waters off the coast of Crimea. Britain rejected Russia’s account of the incident.

Sea Breeze 2021 will last two weeks and involve about 5,000 military personnel from NATO and other allies, and around 30 ships and 40 aircraft. U.S. missile destroyer USS Ross and the U.S. Marine Corps will take part.