President Yoon Suk Yeol (second from left) enters the meeting room to preside over a Cabinet meeting in his office in Seoul Tuesday. (Yonhap)

President Yoon Suk Yeol on Tuesday criticized liberal politicians, including his predecessor Moon Jae-in, for advocating the recognition of North and South Korea as separate states, denouncing the proposal as "unconstitutional."

"North Korea is now threatening a nuclear attack while recognizing its relationship with South Korea as belligerent. In this context, how can someone dare to bring up the concept of the peaceful coexistence of the two Koreas?" Yoon said at a Cabinet meeting held in his office in Seoul.

"These anticonstitutional ideas deny the constitutional obligation to push for a peaceful reunification as enshrined in the Constitution, based on the spirit of freedom and democracy," Yoon said.

The confrontation between the two Koreas will give way to genuine peace on the peninsula through strong power and principle, instead of through hollow promises, Yoon also said.

The remarks apparently referenced former President Moon and Im Jong-seok, who acted as Moon's chief of staff.

The liberal agenda of the two Koreas resurfaced Thursday at a forum to mark the sixth anniversary of the inter-Korean comprehensive military agreement, which gradually became dysfunctional in the wake of the Yoon administration. At the forum, Moon said the current discourse over peace and reunification on the Korean Peninsula should be scrapped completely.

Im at the same event called for the introduction of the a two-state system on the peninsula to stop pursuing reunification. He also urged the removal of the National Security Act aimed at curbing pro-North activities in South Korea, and the revision of the Constitution that stipulates the territory of the Republic of Korea as the entire Korean Peninsula and adjacent islands. Failure to do so would undermine Seoul's peace process and reconciliation and dampen ideological conflict, Im argued.

Im reiterated on his Facebook post on Monday the need to introduce a two-state system on the peninsula and freeze the reunification process, adding that, if otherwise, the confrontation between the two Koreas would leave South Korea neglected as the talks between North Korea and the United States proceed.

Yoon criticized the liberal figures' remarks for being self-contradictory.

"Some politicians claim that (Seoul) should stop pursuing reunification of the two Koreas and even stop bringing up the (agenda of) reunification," the conservative President said.

"They dedicated their lives to reunification campaigns as if reunification were their lifetime goal, and now they abruptly shifted their stance. I can hardly understand these people," Yoon also said, in an apparent reference to Im who was formerly a pro-democracy activist convicted of aiding a South Korean's illegal visit to Pyongyang.

Im in 2019 said he would remain committed to reunification as he declared he would no longer pursue a career as a politician.

Yoon added he would never cater to liberal figures' claim that Seoul should ditch its peaceful reunification initiatives in the "Aug. 15 Unification Doctrine," prioritize peace over reunification, shut down the Ministry of Unification and revise the Constitution.

"A security threat will inevitably escalate on the Korean Peninsula if we give up on our reunification process," he said.

Earlier on Thursday, an official of the presidential office who accompanied Yoon's visit to Prague, the Czech Republic, told reporters that people who sympathize with the concept of peaceful coexistence would "sympathize with the intention of the North Korean regime."

Separately, the official suggested that Im's proposal resembled one for a confederation of two Koreas. The late North Korean founder Kim Il-sung had proposed forming such a confederation as a step to unification.

North Korea has not only test-fired missiles but also sent over 5,500 filthy balloons in dozens of batches, and conducted GPS jamming attacks, after Pyongyang declared in December 2023 that reunification "can never be achieved" and described the two Koreas as "states hostile to each other."

Shin Won-sik, Yoon's national security adviser, said in a televised interview Monday there was a chance of North Korea's seventh nuclear test for small nuclear warhead development in times around the United States presidential election in November to leverage its negotiation with Washington.

Meanwhile, the conservative leader during the Cabinet meeting also slammed his political opponents for spreading rumors that a South Korean group selected as the preferred bidder in the Czech Republic's nuclear energy project in July had put an extremely low bid that would render the nuclear energy deal unprofitable.

Yoon described the opposition parties' predatory pricing claim toward the South Korean consortium as "deplorable."

Yoon has been under siege throughout his term since May 2022 as the liberal opposition parties, which has occupied a majority of seats at the National Assembly have long accused Yoon of his interference with an investigation into the death of a Marine Corps conscript in 2023. They also accused first lady Kim Keon Hee of her alleged antigraft rule violation in 2022 and potential involvement in stock manipulation schemes in the early 2010s.

On Monday, Yoon's job approval rating came to 30.3 percent, the highest in a month, according to a poll by Realmeter.