North Korea's nuclear test site will close in May, the South Korean president's office has said.
A spokesman said the closure of the Punggye-ri site would be done in public and foreign experts from South Korea and the US would be invited to watch.
Scientists have said the site may have partially collapsed in September.
On Friday, North Korean leader Kim Jong-un and South Korea's President Moon Jae-in agreed to work to rid the Korean peninsula of nuclear weapons.
Their summit came after months of warlike rhetoric from the North.