The four-day joint South Korea-U.S. military exercises, dubbed “Invincible Spirit,” wrapped up Wednesday.

The two sides conducted naval and air maneuvers aimed at countering and eliminating air and sea threats. Exercises on supplying munitions, refueling at sea and transporting materials were also carried out.

Also on Wednesday, fighter jets of the two nations held live-fire, air-to-ground strikes at a training ground in Gangwon and Gyeonggi Provinces and formation exercises for the second day.

In addition, the navy and army troops trained collaboratively to stop infiltration attempts by North Korean warships.

The two nations will hold the Ulchi Freedom Guardian (UFG) drills in August. In mid-September, they will hold joint exercises in the Yellow Sea. The joint South Korea-U.S. drills will be held each month into the end of the year.

The U.S. forces that participated in these exercises will return to their bases in succession.