"Americans should sleep well at night", he said.
While the latest report assumes significance in the current climate of heightened tensions between the USA and North Korea, it represents only more certainty over previous assessments.
Earlier on Tuesday, President Trump was quick to highlight his administration's success in leading the UN Security Council to unanimously pass sanctions on North Korea. It cited a military statement made a day earlier, before Trump's remarks.
It cited the need to contain the USA major military bases on Guam, including the Anderson Air Force Base, where US strategic bombers are based. The bombers were joined by Japanese and South Korean aircraft. "Of course, we have to provide all options to do that, and that includes a military option", McMaster said in an interview with MSNBC on Saturday.
Guam's governor, Eddie Calvo, released a two-minute video message to the island's residents, in which he said, "I want to ensure that we are prepared for any eventuality".
Charfauros is in regular contact with the federal Department of Homeland Security and the Department of Defense.
NO CAPABILITY YET U.S. nuclear expert Siegfried Hecker, who has repeatedly visited North Korea's nuclear facilities, said he doesn't think North Korea now has weapons systems for "enveloping fire" around Guam, as it threatened. "They developed these weapons to prevent an attack from the US".
"I take exception to the President's comments because you've got to be sure that you can do what you say you're going to do".
But Democrats slammed Trump for a reaction they charged was "bombastic" and "unhinged".
Meanwhile, California Democratic Sen. Dianne Feinstein said in a statement.
Siegfried Hecker, a professor at Stanford University's Center for International Security and Cooperation, said Tuesday night in the USA that although the North tested two intercontinental ballistic missiles last month, developing a nuclear warhead for such a missile is "extremely challenging and still beyond North Korea's reach".
ENERGY: Benchmark U.S. crude added 28 cents to $49.45 per barrel in electronic trading on the New York Mercantile Exchange.
Guam hosts various types of high-profile USA military weapon systems, including B-1B and B-52 strategic bombers, as well as the THAAD missile defense system.
While Kim's efforts to develop a missile capable of delivering a nuclear weapon to the continental USA face big technological hurdles, he has made significant progress.
However, there's debate within the intelligence community that Pyongyang has the required skill and technology.
The assessment was made by the Defense Intelligence Agency last month, the paper said, marking another alarming development in the communist country's pursuit of nuclear-tipped ballistic missiles that can reach the United States mainland.
"It was a gut-punch to North Korea, to let them know the worldwide community is exhausted of it and we're going to start fighting back", Haley said on "The Story" earlier this week.
A USA strike against North Korea would need the support of South Korea, he said, because the North would likely retaliate against the South and its 600,000 troops. "They will be met with fire and fury".
Another was released soon after which broadened the threats leveled against the U.S. mainland.
Sullivan noted that if North Korea were to attack the U.S., "the President, as commander in chief, has more authority to react to that".
Australian Prime Minister Malcolm Turnbull says North Korea is reckless, provocative, unsafe and a threat to peace.
They hold the USA partly responsible, saying Trump's heated rhetoric is fueling the flames.
"It's one thing to make a mistake intentionally, its another thing to stumble into a conflict. either one - Kim Jong Un or Donald Trump - could miscalculate and let loose a war unlike anything we have seen since World War II".
The nuclear-armed Korea fired an ICBM, called the Hwasong-14, on July 4, followed by another one that traveled a longer distance in late July.
He added that the U.S. "routinely uses" Aegis-equipped warships around the island chain of the Marianas, of which Guam is the largest.
The Korean War started in 1950.