North Korea has formally named Kim Song as its new ambassador to the United Nations, a position that has been vacant for more than a month, state media reported Thursday.

The appointment came after he recently received his visa to begin work at his post in New York. Because his visa was not issued soon after his application in late May, there was talk that the United States was intentionally delaying the process amid slow progress in denuclearization talks with North Korea.

Kim had previously been posted in New York as a counselor with the country's mission. His predecessor, Ja Song Nam, left at the end of July after having served as North Korea's top representative at the U.N. headquarters since February 2014.

(U.N. headquarters in New York)

The White House said Monday that Washington is looking at a second summit between President Donald Trump and North Korean leader Kim Jong Un after the latter made a written request for such a meeting.

In the first-ever U.S.-North Korea summit, Kim committed to "complete" denuclearization of the Korean Peninsula. But Pyongyang has yet to provide a full inventory of its nuclear weapons and fissile materials, as Washington has demanded.

Nor has North Korea presented a road map for denuclearization, except for Kim saying recently he hopes to achieve denuclearization before the end of Trump's first term in January 2021.

The North, for its part, has insisted that the United States first declare a formal end to the Korean War, which was halted with an armistice rather than a peace treaty in 1953.