North Korea says it has completed its first military spy satellite, and leader Kim Jong-un has approved final preparations for a launch to place it in orbit, without publicising a date.

Commercial satellite imagery from Monday shows that progress on a new launch pad in a coastal area east of North Korea’s Sohae Satellite Launching Station is moving forward at a “remarkable pace”, 38 North, a Washington-based programme that monitors North Korea, said in a report on Thursday.

“While the key components of the Sohae complex have been undergoing modernisation and expansion over the past year, this uptick in activity suggests a new level of urgency in making the site ready to accommodate satellite launches,” the report said.

The new launch pad appears to feature a rail-mounted assembly structure, a possible mechanism for lifting a rocket into place, lighting towers, and a tunnel for funnelling flames away.

If it is meant to service liquid-fuelled rockets, additional infrastructure will most likely be needed, the report added.

At Sohae’s main launch pad, crews appear to have completed modifications to the gantry tower, while work continues on storage for fuel and oxidiser.

A new area for VIPs to observe launches also appears largely completed, 38 North concluded.

Analysts say a military satellite is part of the reclusive, nuclear-armed state’s efforts to advance surveillance technology, including drones, to improve its ability to strike targets in the event of a conflict.

North Korea has tried several times to launch “earth observation” satellites, of which two appeared to have been successfully placed in orbit, including the latest in 2016.

International observers have said the satellite seemed to be under control, but there was lingering debate over whether it had sent any transmissions.