The South Korean government says North Korea's criticism of President Yoon Suk Yeol is a reflection of its isolation and sense of crisis.

Speaking to reporters on Tuesday, an official from the unification ministry said the expansion of such sentiments in Pyongyang are being detected as Seoul's state policy centered on freedom and solidarity wins firm support from the international community.

Calling Pyongyang's criticism "low level," the official urged the regime to end its threats and provocations, while also calling for participation in Seoul's "bold initiative" to achieve denuclearization, peace and prosperity on the Korean Peninsula.

Citing a posting under the alias Kim Yun-mi, the North's state-run Korean Central News Agency slammed Yoon's warning about the regime's possible arms trade with Moscow at the UN General Assembly last week.

The article had called Yoon a "political layman" and a "diplomatic idiot" who issued "hysterical" and "ludicrous" remarks.

While the North previously criticized Yoon through an official media outlet 19 times since he took office last May, it was the first time criticism was issued under an unknown individual's name.