Kim Yo-jong, the sister of North Korean leader Kim Jong-un, on Tuesday slammed the US and South Korea over their joint military drills, vowing to build up Pyongyang’s nuclear weapons in response.

In a statement carried by Pyongyang’s official Korean Central News Agency (KCNA), Kim Yo-Jong said, “They (exercises) are the most vivid expression of the US hostile policy, designed to stifle our state by force, and an unwelcoming act of self-destruction for which a dear price should be paid as they threaten the safety of our people and further imperil the situation on the Korean Peninsula.