Joe Biden ‘senile’, brave but ‘irresponsible’, Kim Jong Un’s sister fumes

Kim Yo Jong called US President Joe Biden 'senile' and 'too miscalculating and irresponsibly brave' for his remarks.

Kim Yo Jong, sister of North Korean leader Kim Jong Un, issued a warning to the US and South Korea as the countries signed a new nuclear weapons agreement while calling US President Joe Biden 'senile' and 'too miscalculating and irresponsibly brave' for his remarks.

Kim Yo Jong, sister of North Korean leader Kim Jong Un, delivers a speech.(AP)

“When we consider that this expression was personally used by the president of the US, our most hostile adversary, it is threatening rhetoric for which he should be prepared for far too great an after-storm,” Kim Yo Jong was quoted as saying by state news agency KCNA.

"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-defence will become in direct proportion to them," she added.

“The pipe dream of the US and (South) Korea will henceforth be faced with the entity of more powerful strength," she further said.

This comes as Joe Biden said that Kim Jong Un's regime would cease to exist if he were to launch a nuclear attack on the United States or its allies.

"A nuclear attack by North Korea against the United States or its allies or partners is unacceptable and will result at the end of whatever regime were to take such an action," Biden had said earlier this week.