The national security advisers of the U.S., South Korea and Japan held their first trilateral meeting in Hawaii on Thursday, discussing joint responses if North Korea conducts a seventh nuclear test, according to Seoul’s presidential office.

U.S. and South Korean authorities have warned for months that the DPRK has completed preparations for a nuclear test, though Pyongyang has yet to carry one out.

“Should North Korea conduct its seventh nuclear test, our reaction will definitely be different from those until now,” Kim Sung-han, director of Seoul’s National Security Office, reportedly said after the meeting, according to Yonhap News Agency and