A U.S.-based website that monitors North Korea says there are signs indicating that North Korea is expanding a railway line into the Sohae Satellite Launching Station where the North develops rockets.

In an article posted on its website on Tuesday, 38 North made such an assessment, citing commercial satellite imagery of the station in North Pyongan Province.

According to the article, the Sohae complex is connected to the North’s railway network via a single-track 15-kilometer track line that links up at Tongrim with the Pyongui Line that runs between Pyongyang and Sinuiju.

The website states “the line into Sohae splits into two just ahead of a covered rail transfer building, with one spur terminating in the transfer building and the other continuing beneath the main launch pad.”

It added that “the new rail spur under construction will apparently run from a point just north of the transfer building and head down towards a new horizontal assembly building that is under construction where the old control building used to stand.”

The report said while construction on the rail bed is close to being completed, actual tracks have yet to be laid. 

The website assessed that the latest move, which comes alongside the North’s significant modernization efforts, “underscores North Korea’s expectations for increased satellite launching activity and long-term usage of the site.”