SEOUL, Dec. 6 (UPI) -- A new satellite image discovered an active North Korean missile base that recently underwent construction despite North Korea's pledge to denuclearize its nuclear weapons and missiles, CNN reported.
The image showed that North Korea had been constructing a large underground facility at the Yeongjeo-dong missile base in a mountainous region of the country. The construction reportedly continued from 2017 to August 2018, based on the images.
A South Korean defense official said in a Yonhap News report that South Korean and the U.S. military are aware of this site and the site has been under watch since 1999.
The U.S. and South Korean military officials discovered an unusual construction activity in the mid-1990s in the North Korea-China border region of Yanggang Province. In 1999, officials identified that the site was built to function as a missile base for Rodong medium-range ballistic missiles, according to Joongang Ilbo.
Shin Jong-woo, a researcher at Korea Defense Security Forum, said that the satellite image, obtained by CNN, captured North Korea's recent activity to upgrade the missile base to accommodate its missile renewal.
North Korea's missile-related activity violates the United Nation's resolutions, adopted to condemn North Korea's missile and nuclear weapons development.
A series of resolutions and sanctions have been adopted by the U.N. that calls on the regime to cease any nuclear and missile-related activities.
North Korea runs several underground ballistic missile bases in northern mountainous regions, according to the Joongang Ilbo report.