Satellite images show North Korea expanding a uranium enrichment plant at its Yongbyon nuclear complex.
Experts said it was a sign that the country intended to increase production of weapons-grade uranium by 25 percent.
A report from the Middlebury Institute of International Studies in Monterey said photographs taken by Maxar showed construction in a plot adjacent to the Yongbyon plant.
The report said a photo taken on September 1 showed an excavator at a site where trees were cleared and land was prepared for construction.
A second image taken on 14 September shows foundation work, a new wall enclosing the area and an access point by removing panels from the side of the existing stud building.
Report co-author Jeffrey Lewis said the new area is about 1,000 square meters (10,760 sq ft), which is enough room to hold 4,000 additional centrifuges currently on site.
Yongbyon also has the capability to produce weapons-grade plutonium and satellite photos from last month show that production had resumed.
At a 2019 summit with Donald Trump, Kim Jong Un offered to destroy the complex in exchange for major sanctions relief, but the Americans rejected what he saw as a limited step in nuclear disarmament.
Some US and South Korean experts speculate that North Korea is secretly running at least one additional uranium-enrichment scheme.
North Korea fired cruise and ballistic missiles into the sea this week, a move condemned by Japan.
Experts said the test reflects a push to boost North Korea’s weapons arsenal amid a standoff in nuclear diplomacy between Pyongyang and Washington.
Additional reporting by The Associated Press
Credit: www.independent.co.uk /