Kim Yo-jong, center, the younger sister of North Korean leader Kim Jong Un arrives to attend a meeting of Russian President Vladimir Putin and North Korea's leader Kim Jong Un at the Vostochny cosmodrome outside the city of Tsiolkovsky, Russia, Sept. 13, 2023. AP

The powerful sister of North Korean leader Kim Jong-un has unleashed a sarcasm-filled tirade over President Yoon Suk Yeol's New Year's Day address that unveiled a plan to complete a sturdier deterrence system with the United States to counter North Korean threats this year.

In a statement late Tuesday night, Kim Yo-jong, a vice department director of the ruling Workers' Party's Central Committee, said that the deterrence plan has again given justification for the North to spur efforts to secure "more overwhelming" nuclear forces.

During the speech, Yoon highlighted his pursuit of "genuine and lasting peace" through strength and laid out a plan to devise an improved deterrence system in the first half of the year.

"I cordially welcome ROK President Yoon Suk Yeol's pledge to continuously render 'distinctive services' to the rapid development of our state's military superiority in the new year, too," Kim said in the statement carried by the North's official Korean Central News Agency.

ROK stands for South Korea's official name, the Republic of Korea.

Kim sarcastically accused Yoon of being credited with making security anxiety "commonplace" in South Korea.

Touching on the cross-border policy of Yoon's predecessor, former President Moon Jae-in, she claimed that Pyongyang, caught up in Moon's peace drive, "lost a lot of time" during which North Korea should have enhanced its combat efficiency.

During his presidency from 2017-2022, Moon doubled down on his drive for inter-Korean reconciliation and cooperation, but his efforts stalled following a no-deal Hanoi summit between then U.S. President Donald Trump and the North Korean leader in 2019.

South Korea's unification ministry lambasted Kim's statement as a "petty trick" aimed at shifting the blame on Seoul over heightened inter-Korean tensions.

"Kim Yo-jong's statement is merely a petty trick by a North Korean official who doesn't even fit the bill to distort and denigrate our country's head and the government in regard to the current situation," Kim In-ae, deputy ministry spokesperson, said in a statement.

The ministry official dismissed Kim's claim that North Korea wasted its time during the Moon administration as a "lie," pointing out that Pyongyang has never ceased its development of nuclear and missile programs.

Seoul's defense ministry dismissed Kim's statement as a "forced claim that makes no sense," likening it to a criminal blaming an innocent civilian or the police for committing a crime.

"While establishing a firm readiness posture, our military will punish any North Korean provocation immediately, strongly and until the end," it said in a statement.

The North has been ratcheting up tensions recently with ballistic missile tests and tough rhetoric against the South and the U.S.

Concluding the plenary meeting of the Central Committee of the Workers' Party of Korea on Saturday, the North Korean leader put forth the goal of launching three more military spy satellites as well as adding to its nuclear arsenal this year. (Yonhap)