He added he's looking forward to working cooperatively with the UN.

After the ceremony, he faced a barrage of questions from reporters on inter-Korean relations and the outlook for nuclear negotiations. But he remained tightlipped.

His predecessor, Ja Song-nam, left the UN in late July after a four-year stint in New York.

A graduate of Pyongyang University of International Affairs, Kim had previously been posted in New York as a counselor with the country's mission.

He's also known to have led the North Korean Foreign Ministry's treaty bureau.

He was a member of Pyongyang's negotiating team in Malaysia over the handling of the assassination of Kim Jong-nam, the half-brother of Kim Jong-un, last year.

The North's mission to the UN is widely known as the "New York channel," having often served as a key communication line with the United States. The two sides have no formal diplomatic ties each other.

Emboldened by the outcome of inter-Korean summit talks earlier this week, Secretary of State Mike Pompeo announced that Washington will soon restart talks with the North.

In his talks with President Moon Jae-in, the North's leader reaffirmed his commitment to a nuclear-free Korea and agreed to allow foreign experts to monitor the removal of a major missile engine testing facility and launch pad near the border with China.

He also said his regime could permanently shut down the nuclear complex in Yongbyon if Washington takes reciprocal steps, although these have not been publicly specified. (Yonhap)