The North Korean leader’s sister and a top military official have denounced U.S. military drills with South Korea and Japan this week as a “reckless show of force,” issuing a pair of statements threatening unspecified countermeasures.

The rebukes from Kim Yo Jong and senior military official Pak Jong Chon came a day before the start of trilateral Freedom Edge exercises south of the Peninsula, which will reportedly run concurrently with the U.S.-ROK tabletop drill Iron Mace focused on integrating conventional and nuclear forces.

In her statement, Kim warned that if the exercises reflect the continued embrace of joint nuclear guidelines