South Korean F-15K combat jets have flown nonstop to Alaska, using in-flight refueling to take part in an upcoming U.S.-led "Red Flag" multinational exercise, Seoul's Defense Ministry said Friday.

The flight to Alaska was the "first time" South Korean fighter aircraft have flown nonstop by aerial refueling to participate in a joint drill overseas, spokesman Wi Yong-seop told a news briefing.

Wi added that South Korean pilots are expected to further improve their skills by joining the multinational drills, hosted by the U.S. Pacific Air Forces. The drills are scheduled to kick off Monday.