South Korean President Yoon Suk-yeol slammed North Korea as an “irrational group” for developing nuclear weapons and rejecting the concept of shared Korean ethnicity, speaking in back-to-back high-level defense meetings on Wednesday.

Yoon’s remarks came a month after North Korean leader Kim Jong Un declared that South Korea is no longer a compatriot but a warring, foreign state that Pyongyang will prepare to one day subjugate.