Specialists at the James Martin Center for Nuclear Nonproliferation Studies in California said satellite images on Friday showed signs of activity at the site, including the construction of a new building and the repair of another.
“The construction and repair work shows that North Korea has made some decision regarding the test site,” the report said.
North Korea closed the site, called Benji-ri, in 2018 when it unilaterally declared a temporary moratorium on nuclear weapons tests, but North Korean leader Kim Jong Un said the moratorium is no longer binding as denuclearization talks have stalled.
The James Martin Center experts confirmed that the changes that occurred on the site occurred during the past few days, and it is still difficult to determine precisely what is being built and for what purpose.
“It is possible that North Korea intends to make the site ready for nuclear explosions,” the report said, but experts say it could take months and possibly years for the site to be ready for nuclear explosions.
Talks aimed at persuading North Korea to give up its arsenal of nuclear weapons and long-range ballistic missiles have been stalled since 2019.