The sister of North Korea’s leader has hit out at U.S. President Joe Biden following a new U.S.-South Korean agreement to intensify nuclear deterrence. Kim Yo Jong rejected Biden’s comments that North KOrean nuclear aggression would result in the end of its regime, calling him senile and “too miscalculating and irresponsibly brave.” She said North Korea wouldn’t simply dismiss his words as a “nonsensical remark from the person in his dotage.” “When we consider that this expression was personally used by the president of the U.S., our most hostile adversary, it is threatening rhetoric for which he should be prepared for far too great an after-storm,” she said. “The more the enemies are dead set on staging nuclear war exercises, and the more nuclear assets they deploy in the vicinity of the Korean Peninsula, the stronger the exercise of our right to self-defense will become in direct proportion to them.”