North Korean leader Kim Jong Un ’s powerful sister yet again taunted South Korean efforts to improve ties, state media reported Wednesday, saying that her country will never accept Seoul as a diplomatic partner.

Kim Yo Jong, a senior official on the State Affairs Commission, called South Korean President Lee Jae-myung’s push for improved ties a “pipe dream,” according to a statement published by the Korean Central News Agency. She accused Lee or trying to create an “amicable image” while hosting a large-scale military exercise with the United States.

SEOUL, South Korea (AP) — North Korean leader Kim Jong Un condemned South Korean-U.S. military drills and vowed a rapid expansion of his nuclear forces to counter rivals, state media said Tuesday, as he inspected his most advanced warship being fitted with nuclear-capable systems.