South Korea and the United States will kick off a combined large-scale air exercise Thursday.

According to South Korea’s Air Force on Thursday, the air forces of the two nations will conduct the Freedom Flag exercise for two weeks until May 2, mobilizing some 90 air assets and eleven-hundred personnel from the two sides. 

The participants will conduct key missions, including air interdiction, combat research and rescue, and close air support missions, and will undergo training in wartime operational procedures. 

The fifth-generation stealth fighters F-35A and F-35B will serve as simulated enemy aircraft for the first time.

Unmanned aerial vehicles such as the U.S. air force’s MQ-1 and MQ-9 will also take part, allowing for integrated training with manned and unmanned aerial assets. 

South Korea and the U.S. hold the Freedom Flag exercise twice a year, replacing regular large-scale joint air exercises — Korea Flying Training in the first half of the year and Vigilant Defense in the second half.