Seoul (CNN) North Korean leader Kim Jong Un will shut down his nuclear test site in May and invite experts and journalists from South Korea and the United States into the country to ensure "transparency" around its closure, South Korea's presidential office said Sunday.

It is the latest breakthrough on the peninsula ahead of a meeting between Kim and US President Donald Trump, who said Saturday that talks could take place within "three to four weeks."

A senior spokesman for South Korean President Moon Jae-in said Kim made the comments during a landmark summit Friday at the demilitarized zone between the two countries, when Kim became the first North Korean leader to step into South Korean territory since fighting ended in the Korean War in 1953.

Kim told Moon during the summit that he had no intention of targeting the US or the South with nuclear weapons, the South Korean President's office said Sunday.

"The United States, though inherently hostile to North Korea, will get to know once our talk begins that I am not the kind of person who will use nuclear weapons against the South or the United States across the Pacific," Kim was quoted as saying by Moon's spokesman Yoon Young-chan on Sunday.