Satellite imagery from last week shows that North Korea has halted the dismantling of a key missile engine testing site amid an apparent impasse in negotiations with the United States on its denuclearization, a monitoring group has said.

An analysis published Wednesday of imagery taken Aug. 16 of Sohae Satellite Launching Station, the North's main satellite launch facility since 2012, indicated there has been "no significant dismantlement activity" at either the site's engine test stand or launchpad since Aug. 3, according to 38 North, a prominent North Korea monitoring group.

The report said that while there had been significant progress in tearing down the test stand from July to early August, "the components previously removed remain stacked on the ground."