U.S. analysts claim North Korea has quietly built an intercontinental ballistic missile base that is larger and more capable than an older, well-known launch pad.

The Associated Press (AP) Thursday quoted independent analysts as saying that construction of the base on North Korea's west coast began at least eight years ago. The analysts that provided images of the secret site are Joseph Bermudez, senior analyst with Jane's Information Group, and Tim Brown with Talent-keyhole.com, a private satellite imagery analysis company.

According to the AP, Bermudez first located the site in early spring and tracked the site’s construction using commercial and unclassified satellite imagery.

Bermudez said the primary purpose of the facility is to test missiles, but that any base capable of a long-range test could also be used in wartime to launch a missile tipped with a warhead.