The U.S., South Korea, and Japan launched Freedom Edge, a large-scale air and naval drill near South Korea’s Jeju Island, running through Friday.

The exercise, billed as their most advanced trilateral defense cooperation to date, includes missile defense, maritime operations, and cyber training to counter North Korea’s nuclear threats.

Pyongyang denounced the drills as a “reckless show of strength,” with Kim Yo Jong warning of consequences, the Associated Press has reported.

North Korea has rejected talks with Washington and Seoul, instead deepening ties with Russia and China while continuing weapons development.