TOKYO - The influential sister of North Korean leader Kim Jong Un rebuffed Seoul's offer of economic benefits in exchange for denuclearization steps, calling South Korean President Yoon Suk-yeol "really foolish" and his plan "absurd" on Friday.

In characteristically descriptive language, Kim Yo Jong released a statement titled "Don't have an absurd dream" through state media, emphasizing that her country has no intention of giving up its nuclear and weapons program for economic cooperation with the South. Along the way, she swiped at the South Korean leader over his plummeting approval ratings, which reached 24% after three months in office.

"No one barters its destiny for corn cake," Kim wrote.

This week, Yoon released details of an economic assistance package that he had announced during his May 10 inauguration speech. In return for Pyongyang taking steps to disarm, the South would help it with food, health care, agriculture and infrastructure, Yoon said, without addressing the North's desire for international sanctions relief. While Yoon described his plan as "audacious," previous South Korean leaders have made similar proposals that have failed, while Kim Jong Un has shown no sign of relinquishing a nuclear deterrent he views as his regime's ultimate security guarantee.

On Friday, Kim Yo Jong, one of the most powerful officials in the North Korean regime, called Yoon's' plan "an impracticable one to create mulberry fields in the dark blue ocean."

She described it as a replica of "Vision 3000 through Denuclearization and Openness," a proposal by former conservative South Korean president Lee Myung-bak to push North Korea toward denuclearization in exchange for massive aid and investment that he pledged would raise North Korean income levels to $3,000 per capita. Yet inter-Korean relations worsened during Lee's term. North Korea is now believed to be preparing for its seventh nuclear test; its per capita income was estimated at $1,083 in 2021.

"The fact that he copied the policy towards the north, thrown into the dustbin of history, and called it 'bold plan' shows that he is really foolish," she wrote, adding that Yoon had "uttered pipedream-like remarks" that made him look "miserable."

On Friday, Yoon's office expressed regret over Kim Yo Jong's attacks, saying that North Korea made "rude remarks" and "distorted" the president's proposal. An administration official earlier this week had rejected comparisons to Vision 3000, saying Yoon's plan was an "upgrade."

Meanwhile, the South Korean and U.S. militaries are gearing up to resume full-scale exercises next week for the first time in about five years, a move that could raise tensions with North Korea amid the diplomatic standstill between Washington and Pyongyang. The allies had suspended or downsized drills after 2017 as they sought to engage North Korea through diplomacy and denuclearization talks.

Yoon has emphasized his country's security alliance with the United States and the importance of strengthening deterrence measures in the face of growing nuclear threats from the North. He has promised to increase Seoul's defensive capabilities while leaving open the door for talks with North Korea. Military drills have long been an irritant for Pyongyang, which views them as preparations for an invasion of the country.

Yoon's economic announcement earlier this week was followed by preliminary exercises for next week's drills. Pyongyang then launched two cruise missiles off its west coast, breaking a two-month testing hiatus.

The Washington Post's Min Joo Kim in Seoul contributed to this report.