WASHINGTON -- North Korea appears to be nearing completion of a ballistic missile facility with the capacity to test-fire intercontinental ballistic missiles, an expert with a US think tank said Tuesday.

The Sil-li Ballistic Missile Support Facility, which was "previously undisclosed," is approximately 17 kilometers northwest of Pyongyang and close to Pyongyang International Airport, Joseph Bermudez wrote in a report for the Center for Strategic and International Studies. His conclusions are based on satellite imagery.

"A new facility is nearing completion near Pyongyang International Airport that is almost certainly related to North Korea's expanding ballistic missile program," he wrote. "A high-bay building within the facility is large enough to accommodate an elevated Hwasong-15 intercontinental ballistic missile and, therefore, the entirety of North Korea's known ballistic missile variants."

According to Bermudez, construction on the facility began in mid-2016. It is next to an underground facility that is likely large enough to fit all known North Korean ballistic missiles, their associated launchers and support vehicles.

The facility's unique characteristic include interconnected buildings designed for drive-through access, its relatively close location to ballistic missile component manufacturing plants in the Pyongyang area, and a raised center section, or high-bay, on the largest building.

"Significantly, the building has a 37-meter-by-30-meter elevated center section (i.e., a high-bay) that is high enough to allow for a Hwasong-14 or Hwasong-15 intercontinental ballistic missiles (ICBM) on a TEL to be easily elevated into the firing position to allow for testing of both, as well as the training of maintenance and ground crews," the report says, referring to transporter-erector-launchers.

Bermudez said these characteristics suggest the facility is likely designed to support ballistic missile operations.

"As such, it is another component of the North Korean ballistic missile infrastructure that has been undergoing both modernization and expansion during the past 10 years," he said.

"While the precise function of the facility is unclear," he added, "its configuration and the size of its buildings and (underground facility) indicate that it can be used for the assembly of ballistic missiles from components delivered by rail from nearby ballistic missile component factories (e.g., Tae-sung Machine Factory, Mangyongdae Light Electric Factory), accommodate all known and anticipated North Korean ballistic missiles and their transporter-erector-launchers (TEL), mobile-erector-launchers (MEL) or transporter-erectors (TE) for depot-level maintenance, storage of ballistic missiles and their transporters, or any combination of these functions."

Bermudez predicted that at the current pace of construction the facility may be complete and ready for operations sometime during late 2020 or early 2021. (Yonhap)