North Korean leader Kim Jong-un visits a training base of the army's special operations forces, Sept. 11, in this photo provided by the North's official Korean Central News Agency. Yonhap

North Korean leader Kim Jong-un has strongly criticized South Korean President Yoon Suk Yeol, calling him an "abnormal man" for talking about military action against the nuclear-armed North, state media said Friday.

On Tuesday, Yoon said in an Armed Forces Day ceremony that North Korea will face the end of its regime if it attempts to use nuclear weapons, warning of a "resolute and overwhelming" response from the South Korea-U.S. alliance.

"The puppet Yoon bragged about overwhelming counteraction of military muscle at the doorstep of the state possessed of nuclear weapons and it was a great irony that caused the suspicion of being an abnormal man," Kim said during a visit to a training base of the North's special operation units Wednesday, according to the Korean Central News Agency (KCNA).

Yoon's address showed the "security uneasiness and irritating psychology of the puppet forces" and amounts to acknowledging that it is none other than South Korea and the United States that are "destroying regional security and peace," Kim said, according to the KCNA.

It marks the first time in about two years that Kim has issued such strong remarks about Yoon without addressing him as president, the last instance being in July 2022 during a speech marking the 69th anniversary of the armistice that halted the 1950-53 Korean War.

Transporter erector launchers carrying Hyunmoo-5 ballistic missiles move on the tarmac at Seoul Air Base in Seongnam, Gyeonggi Province, for South Korea's Armed Forces Day ceremony on Oct. 1. Yonhap

Kim was accompanied by high-ranking KPA officials, including Ri Yong-gil, chief of the KPA General Staff, during the inspection, which was aimed at observing the combat drills of the special operations forces, the KCNA said.

On Thursday, Kim's influential sister, Kim Yo-jong, called South Korea's Armed Forces Day ceremony "foolish" and the Hyunmoo-5 missile, first showcased during the event, a "weapon of worthless large bulk."

She also claimed that the North's multiple rocket launcher is "calculated to be equal to 900 tons of explosive power in terms of the explosive capacity of a conventional warhead," in an apparent comparison with the Hyunmoo-5 missile that is known to be capable of carrying an eight-ton warhead.

The South's military downplayed such a claim, raising the possibility of deception.

"It is impossible in terms of a conventional weapons system," a Joint Chiefs of Staff (JCS) official told reporters. "There is a possibility of deception and it does not make sense logically."

The JCS official said the military is taking necessary preparation measures against the North's verbal threats and assessing the details of the North's back-to-back statements.

The South's disclosure of the Hyunmoo-5 missile on two 9-axled transporter erector launchers on Tuesday was seen as an apparent warning against North Korea's nuclear and missile threats, with the powerful missile known to be able to target anywhere in the North. (Yonhap)