Pilots and airmen from the 80th Fighter Squadron from Kunsan Air Base, South Korea, are in Singapore this week for fighter jet training with Singaporean forces — one of the only exercises that provides live “dissimilar” training against aircraft of another country, Air Force officials reported.

The annual Commando Sling, started 15 years ago, takes place in four phases between October and July. The second phase, which began March 1, includes personnel and six F-16s from Kunsan.

Crews from Misawa Air Base, Japan, completed the training in November. Kunsan will participate again in May, and in July, Marines from Marine Corps Air Station Iwakuni in Japan will participate, according to Pacific Air Forces.

During the training, U.S. Air Force F-16s and Marine Corps F/A-18s fly against Singaporean F-5s, A-4s and F-16s.

The exercise is coordinated and hosted by the U.S. Air Force’s 497th Combat Training Squadron, based in Singapore. It provides training in offensive and defensive counter air operations, air and missile defense and deployment training, according to PACAF.