Activity has been detected at a North Korean long-range rocket site, suggesting Pyongyang may be pursuing the "rapid rebuilding" of the facility after the collapse of the Hanoi summit, according to analysis of satellite imagery.
Last week's meeting between North Korean leader Kim Jong Un and US President Donald Trump ended abruptly after the pair failed to reach an agreement on walking back Pyongyang's nuclear programme in exchange for sanctions relief.
The renewed activity was recorded two days after the summit and may "demonstrate resolve in the face of US rejection" of the North's request for sanctions relief, said researchers at the Washington-based Center for Strategic and International Studies (CSIS).
"This facility had been dormant since August 2018, indicating the current activity is deliberate and purposeful."
Kim had agreed to shutter the Sohae missile-testing site at a summit with the South's President Moon Jae-in in Pyongyang, as part of confidence-building measures, and satellite pictures in August suggested workers were already dismantling an engine test stand at the facility.