ABOARD THE USS CARTER HALL ON THE BALTIC SEA (AP) — The commander of the U.S. Sixth Fleet says NATO ships are conducting a major naval drill in the Baltic Sea without interference from Russia.

Tensions rose in April when Russian jets buzzed a U.S. destroyer in the Baltic Sea, but U.S. Navy Rear Adm. James G. Foggo III said Wednesday that "we've not seen a lot of Russian activity" during the exercise that started June 3.

The drill includes naval forces from 15 NATO nations and nonmembers Finland and Sweden. Foggo said a Russian intelligence vessel is "shadowing" the exercise, but "they've acted very professionally and haven't interfered with our operations."

Earlier this week, Foggo said the exercise sends "a message to any bad actor who would want to disrupt the economic prosperity and the security" of the region.