North Korea is able to hit the West Coast of the United States with a nuclear weapon mounted onto an intercontinental ballistic missile (ICBM), USNI News reported based on a Pentagon intelligence assessment.

Pyongyang would have to launch the weapon from its mobile launcher, the KN-08, which in turn would reduce warning from inside the totalitarian state, revealed the report cited on Thursday by Adm. William Gortney; Gortney heads the North American Aerospace Defense Command (NORAD), which is in charge of protecting U.S. airspace.

"Our assessment is they have the ability to put a nuclear weapon on a KN-08 and shoot it at the homeland, and that's the way we think -- that's our assessment of the process," the admiral told reporters. "We're very concerned about the mobile nature of the KN-08. We lose our ability to get he indication that something might occur and of course the unpredictable nature of the regime that's there," Gortney added.

The statement by the NORAD serves as further confirmation that the United States believes North Korean dictator Kim Jong Un has advanced his nation's nuclear capabilities to the point of threatening the U.S. mainland, Defense News noted.

Jeffrey Lewis, the director of the East Asia Nonproliferation Program at the James Martin Center for Nonproliferation Studies, told the publication that while Kim's regime may in fact be capable of equipping a KN-08 with a nuclear weapon, it still faces a challenge in getting that payload to be effective.

"It's not that hard to (miniaturize the weapon), but what happens is you start to encounter reliability problems, especially if it's got a ride on an ICBM," Lewis said.

But the Pentagon prefers to err on the side of caution when planning for potential threat, the nonproliferation expert explained.

"I think they are getting the underlying intelligence assessments, which say they can make it small enough to fit on the missile," Lewis said. "They can't say North Korea can't do this, because that's not what the assessment says. So it wouldn't surprise me they say they have to assume it works."

Underlining that line of thought, Gortney insisted that it was "prudent" to plan ahead even though there has not yet been a test of a nuclear-capable KN-08.