More than 4,100 military personnel on 40 ships, two submarines and 28 aircraft from 11 nations are taking part in the annual Baltic Operations exercise, which runs from June 3-18.

The annual exercise is designed to increase the nations’ abilities to work together at sea and is co-hosted by Latvia and the United States, officials said last week.

Nations taking part are Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Russia, Poland, Sweden, the United Kingdom and the United States.

U.S. forces taking part in the exercise include the guided missile cruiser USS Anzio, guided missile destroyer USS Cole and dock landing ship USS Tortuga.

BALTOPS, as the exercise is known, will include amphibious landings, at-sea refuelings, ship boarding, anti-submarine exercises, gunnery, seamanship and radar search training. The exercise, according to a Navy press release, includes scenarios based on “real-world crises.”

Carrier Strike Group 12 commander Rear Adm. James Stevenson Jr. will command the exercise from the Anzio, officials said.

This is the 33rd year for the exercise, which is run in the Baltic Sea. BALTOPS will kick off in Latvia before moving to sea, and will wrap up during a port visit in Germany.

Last year’s exercise included more than 5,000 personnel on ships and aircraft from 13 nations.