Just days after Russia threatened to fire on “intruding” warships near the Crimean Peninsula in the Black Sea, the annual Sea Breeze exercise, which U.S. 6th Fleet is co-hosting with the Ukrainian Navy, kicked off Monday with the largest number ever of participating countries.

Sea Breeze 21, which continues through July 10 in the Black Sea region, focuses on amphibious warfare, land maneuver warfare, diving operations, maritime interdiction operations, air defense, special operations integration, anti-submarine warfare and search and rescue operations, according to a 6th Fleet news release.

Thirty-two countries from six continents are providing 5,000 troops, 32 ships, 40 aircraft, and 18 special operations and dive teams to the exercise.

“The United States is proud to partner with Ukraine in co-hosting the multinational maritime exercise Sea Breeze, which will help enhance interoperability and capabilities among participating nations,” said Chargé d’Affaires Kristina Kvien, U.S. Embassy in Ukraine. “We are committed to maintaining the safety and security of the Black Sea.”

The exercise gets underway just five days after Russia announced that one of its warships fired warning shots and a warplane dropped bombs in the path of British destroyer Defender to drive it away from waters near the Crimean city of Sevastopol, the main Russian naval base in Crimea. Britain denied that account, insisted there were no warning shots or bombs dropped near its ship and that it was sailing in Ukrainian waters.

The Russian Defense Ministry said June 23 a patrol ship fired warning shots because the HMS Defender ignored a notice against intrusion and sailed 1.6 nautical miles into Russia’s territorial waters. It claimed a Russian Su-24 bomber also dropped four bombs ahead of the vessel to persuade the Defender to change course. Minutes later, the Defender left Russian waters, the ministry said.

Britain insisted the ship was making a routine journey through an internationally recognized travel lane and remained in Ukrainian waters. The U.K., like most of the world, recognizes Crimea as part of Ukraine despite the peninsula’s 2014 annexation by Russia.

British Prime Minister Boris Johnson would not say whether he had personally approved the Defender’s voyage but suggested the Royal Navy was making a point by taking that route.