Two North Korean missile bases have been active and expanding, according to analysis of satellite images by CNN.
According to CNN, satellite footage shows the Yeongjeo-dong base is still active, and another base seven miles away is being upgraded. The second site appears to be a new facility, although experts that CNN talked to from the Middlebury Institute speculated that the new site may be part of the Yeongjeo-dong base.
Officials from the Pentagon and the State Department told CNN that they could not discuss matters related to national intelligence.
On Tuesday, national security adviser John Bolton stressed that President Donald Trump thinks holding a second summit with North Korean dictator Kim Jong Un at the start of 2019 would help get Kim back on track.
"They have not lived up to the commitments so far," Bolton said. "That's why I think the President thinks that another summit is likely to be productive."
In August, a United Nations watchdog warned that North Korea was still working on developing its nuclear arsenal. In November, the New York Times reported that North Korea was still working on its nuclear missile program at more than a dozen hidden bases, according the Sakkonmol Missile Operating Base, which is about 85 miles from the Demilitarized Zone that separates North and South Korea.
The latest CNN analysis is in addition to these past reports.
What about Kim's promises?
At their June 12 summit in Singapore, Trump and Kim signed a statement that read:
President Trump committed to provide security guarantees to the DPRK, and Chairman Kim Jong Un reaffirmed his firm and unwavering commitment to complete denuclearization of the Korean Peninsula.
Members of the Kim dynasty have promised that they would denuclearize and then backtracked on six separate occasions in 1985, 1992, 1994, 2005, 2007, and 2012.