North Korea continues to develop a mobile intercontinental ballistic missile that "would likely be capable of reaching much of the continental United States," the Pentagon said in a new report to Congress on the secretive regime's military capabilities.

The KN-08 missile would have an estimated range of more than 3,400 miles (5,500 km), and North Korea already has six "road mobile" launchers for it, according to the annual report delivered to congressional committees Friday and obtained by Bloomberg News. A mobile missile can be harder to track than a silo-based weapon, although the threat from the KN-08 depends on whether it's "successfully designed and developed," the Defense Department cautioned.

The new report, reaffirming a judgment about the KN-08 made by the Pentagon in 2013, arrives amid rising tensions after North Korea conducted a nuclear test on Jan. 6 and launched a long-range rocket on Feb. 7. South Korea and the United States have said they will begin talks about deploying an American ballistic missile interceptor system known as THAAD on the Korean Peninsula.