U.S. radio network National Public Radio(NPR) reported Friday that commercial satellite imagery of a facility near Pyongyang suggests that North Korea is preparing to launch a missile or space rocket in the near future.

NPR said the images taken on February 22nd are of a site known as Sanumdong — a facility where North Korea has assembled some of its intercontinental ballistic missiles and satellite-launching rockets. 

The images show cars and trucks parked near the facility and rail cars sitting in a nearby rail yard where two cranes are also erected.

Jeffrey Lewis, director of the East Asia Nonproliferation Project at the Middlebury Institute of International Studies in California, says that "when you put all that together, that's really what it looks like when the North Koreans are in the process of building a rocket."

But he cautions that it's impossible to know whether the North is preparing a military missile or a rocket that could carry a civilian satellite into space, and also impossible to know when any launch might happen.

According to additional images of the Sanumdong site taken Friday by another company, vehicle activity has died down and one of the cranes has disappeared. 

NPR says that could mean that workers have paused work on an ICBM or rocket, perhaps while awaiting further parts, or it could mean a missile or rocket has already left the facility.

Lewis says there's no easy way to tell whether a train has carried a missile or rocket parts and left toward the Sohae Satellite Launching Station because the rail yard there has a roof over it to prevent satellite snooping.

Lewis says he believes it's most likely North Korea is preparing to launch a satellite into orbit.  

South Korea's National Intelligence Service also briefed the Korean parliament about activities at the Sanumdong site while noting that some dismantled facilities at the Dongchang-ri missile launch site were being restored.