Six KF-16 fighter jets of South Korea headed to the US state of Alaska on Thursday to take part in a multinational air combat training led by Pacific Air Forces.

The KF-16s took off at around 5:30 a.m., originally scheduled to arrive in Alaska about 10 hours later, according to South Korea's Air Force.

The flight distance to the Eielson Air Force Base, the venue for the annual RED FLAG-Alaska training, is some 7,700 kilometers.

It's slated to open on June 11 for a 11-day run.

But they made a stopover at the Yokota Air Force Base in Japan due to a change in scheduled aerial refueling, it said.

The KF-16s will resume their flight on Friday toward Alaska.

South Korea will also dispatch a C-130 cargo plane and more than 100 personnel to the series of drills on joint offensive, counter-air operation, interdiction and air support under a simulated combat environment.