A major construction project at a North Korean long-range nuclear missile factory has slowed in recent months in a possible sign of resource or project direction issues, NK Pro analysis of satellite imagery has found, after work started with urgency last summer.

Planet Labs imagery shows that basic framework construction on two large buildings covering around 2.5 acres (1 hectare) outside tunnel entrances at the Thaesong Machine Factory near Pyongyang stalled with little progress between early December and mid-February.

While it remains possible that renovations or installation of new machinery has continued inside the mountainside tunnels, the abandonment of half-finished structures outside suggests the project was poorly planned or is facing shifting priorities.

The apparent slowdown comes as a top U.S. military general made headlines last week for saying DPRK leader Kim Jong Un “is eager to transition his strategic weapons program from research and development to serial production and fielding.”

NK Pro was first to report on the start of the upgrade project last July, detailing evidence that the factory’s western complex, where construction is now taking place, likely housed liquid-fuel engine production lines for intercontinental ballistic missile (ICBM) or satellite carrier rockets in the past.

A separate Thaesong Machine Factory complex just up the road to the east has featured in state media numerous times during the Kim Jong Un era, hosting inspections of nuclear warheads and ICBM assembly, while scenes of Kim Jong Il in the western complex tunnels still appear occasionally on state TV.

The current leader’s most recent confirmed appearance at Thaesong was in Jan. 2023, when state TV released a single photo of Kim and his young daughter in a room full of dozens of intermediate-range ballistic missiles (IRBMs). 

Existing evidence suggests the eastern complex has been used for final liquid-fuel IRBM and ICBM assembly and the western complex for rocket engine production, but additional functions are not confirmed.

The new construction could be related to North Korea’s stated aim of developing a new liquid-fuel engine for the country’s military reconnaissance satellite program.

If construction is indeed related, a likely contributing factor to the delay would be Kim Jong Un abandoning his goal of launching three military satellites in 2024, after the only launch attempt of the year failed in May. 

This would suggest a major reassessment of the program later last year, with as yet unknown implications but likely taking advantage of ongoing military cooperation and weapons trade with Russia.

Another possible purpose of the Thaesong construction project is to renovate the factory in line with Kim’s shift in preference for solid-fuel IRBMs and ICBMs in recent years, though such systems have yet to appear publicly at the Thaesong facilities.

Despite the troubled construction at Thaesong, it is common for important projects in North Korea to face long delays before resuming, so it is too early to determine if the current lack of progress is a sign of larger issues with the country’s missile or satellite programs.

Meanwhile, North Korea has pursued expensive military projects elsewhere in the last year like new warship construction and even major upgrades to other weapons factories, some of which experienced their own delays prior to resurgences in activity.

Edited by Alannah Hill