Kim Yo Jong, the sister of North Korean leader Kim Jong Un, called South Korea's president "a parrot raised by America."
South Korean President Moon Jae-in has criticized his country's neighbor for conducting missile tests last week.
"We can hardly repress astonishment at his shamelessness. He cannot feel sorry for being 'praised' as a parrot raised by America," Kim Yo Jong said Tuesday.
South Korea's Unification Ministry said it was disappointed with Kim's statement. The ministry called on the leaders of both countries to observe the "rules of minimum etiquette."
Kim has previously been seen as a "peace messenger" by South Korea. She visited Seoul and invited Moon to visit Pyongyang in 2018. However, as relations between the two soured Kim has taken the lead in making statements against South Korea.
Experts speculate North Korea's increasingly aggressive language against the U.S. and its allies may be its way of pressuring U.S. President Joe Biden to reshaping its North Korea policies.
