The report, required by law, updates Congress regularly on the status of and changes in North Korea's military capabilities.
While the report, released Friday, was written prior to Pyongyang's recent nuclear test and satellite launch
, it underscores the regime's devotion of large amounts of funding to modernizing its military forces and weapons arsenals.
The report also singles out North Korea's Special Operations forces. It calls them "among the most highly trained, well-equipped, best fed and highly motivated" forces in North Korean leader Kim Jung Un's military.
In other sections of the report, the Pentagon notes North Korea's major Special Operations units "appear designed for rapid offensive operations," including internal defense against foreign attacks.
Kim continues to make public statements detailing his views that the country could come under attack, so this assessment appears to square with his priorities.
North Korea's Special Operations forces "operate in specialized units, including reconnaissance, airborne and seaborne insertion, commandos and other specialties," the report finds.
Defense Secretary Ash Carter discussed concerns about North Korea's military last week in Washington.
"Every single day we are watching that DMZ," he said, referring to the demilitarized zone between North and South Korea. There are about 27,000 U.S. troops stationed in South Korea.
In recent testimony to Congress, CIA Director John Brennan referred to Kim's interested in demonstrating his nuclear and intercontinental ballistic missile capacity to the world.
"He wants to showcase (this capacity)
as a way to demonstrate his strength, but also as a way to help to market some of his proliferation capabilities," he said.
The U.S. worries that North Korea will be able to eventually put a nuclear warhead on a long-range missile.
"The assessment, at least from my perspective, is that he has developed both the nuclear capability as well as developing this ballistic missile capability, marrying them together so that he can demonstrate that he has reached far beyond the Korean Peninsula," Brennan told Congress.
The report also notes that North Korea continues to work on a long-range missile, called the KN-08, that could give North Korea the ability to attack the U.S. with a mobile launcher that U.S. satellites could have trouble tracking.