Kim Jong Un’s influential sister threatened South Korea with a nuclear strike if it tried to attack, in an apparent effort to justify future provocations to challenge the hawkish new president soon taking power in Seoul.

Kim Yo Jong said that if South Korea "opts for military confrontation with us, our nuclear combat force will have to inevitably carry out its duty,” the official Korean Central News Agency reported Tuesday. It was the second warning issued by the younger Kim in about 48 hours, after she earlier denounced South Korean Defense Minister Suh Wook as a "senseless and scum-like guy.”

The comments were the first Kim Yo Jong has made in state media in about six months and indicate that she still serves as the face of Pyongyang’s policies toward Seoul. South Korean President-elect Yoon Suk-yeol is set to take power May 10, after pledging to align more closely with the U.S. and take tougher line toward North Korea and China.