The Pentagon considers these North Korean mobile ballistic missiles a top threat

The Pentagon outlined in a report to congress today that North Korea's mobile intercontinental ballistic missiles (ICBMs) are a top threat to the nation, Bloomberg Business reports.

According to the Pentagon report, Pyongyang has already developed and deployed six "road-mobile" launchers for the KN-08 missile.

Estimations of the missile's range vary, although The Heritage Foundation published in its 2016 Index of US Military Strength that the missiles could have ranges up to 9,000 km.

This estimation was echoed by the Pentagon today, Bloomberg notes, as the military believes that the KN-08 "would likely be capable of reaching much of the continental United States."

The Pentagon did clarify the threat from the KN-08 by saying that "ICBMs are extremely complex systems that require multiple flight tests to identify and correct design or manufacturing defects."

And currently, the missile's reliability is likely extremely low due to a lack of testing.

But the KN-08 remains the most serious missile threat emanating from out of the hermit kingdom.

The KN-08 is a road-mobile intercontinental missile, meaning Pyongyang can move the launch system throughout the country. In contrast, other long-range missiles must be fired from stationary launch pads.

"It's the relocatable target set that really impedes our ability to find, fix, and finish the threat," Adm. Bill Gortney, the commander of NORAD, told reporters in April 2015. "And as the targets move around and we if don't have the persistent stare and persistent [intelligence, surveillance, and reconnaissance] that we do not have over North Korea at this time, that relocatable nature makes it very difficult for us to counter it."

The KN-08 is also different from the Taepodong 3, which North Korea tested earlier in the month. That ballistic missile is nuclear capable with an estimated range of 13,000 kilometers - which would place the entire United States in range.

The missiles, however, are both unlikely to have the accuracy required for precision targeting on large US cities. And although the Pyongyang may soon develop the capability needed to launch missiles towards the US, it's still possible that it wouldn't be able to evade existing US missile defenses.

"Should [a missile] get airborne and come at us, I'm confident we would be able to knock it down," Gortney told reporters.

In the face of such a challenge, the US has agreed to deploy the Terminal High Altitude Area Defense (THAAD) missile system to South Korea.

The missile system is able to knock enemy missiles out of the sky, hopefully limiting the utility of any long-range missiles in North Korea's arsenal.