"We're going to do a great job, don't worry about a thing", Trump then added.
"North Korea better get their act together or they are going to be in trouble like few nations have ever been in trouble", Trump said, flanked by Vice President Mike Pence.
Key Pyongyang ally Beijing, meanwhile, has pleaded with Trump to tone down his rhetoric to prevent tensions from boiling over.
Pyongyang said this week it is planning to launch four missiles into waters near the coast of Guam, which is a major United States military hub with a population of 163,000 - all of whom are technically U.S. citizens.
On Friday, it posted guidelines on its website about measures to take in the event of a nuclear attack. If people are caught outside, "do not look at the flash or fireball - it can blind you". Take cover behind anything that might offer protection. He told the governor that when it came to Guam, "we are with you 1000%".
"Guam is more than a military base. We reassure potential visitors that we continue to be a safe. place to visit".
Trump said the U.S.
After the tourism discussion, the two talked more about North Korea and how to deal with someone like Kim Jong Un and about partisan rancor and obstructionism in Washington, D.C. Marco Rubio, a member of the Senate foreign affairs committee, defended President Donald Trump's stark warning to North Korea in a series of tweets Thursday morning.
"I think we have to be very careful in terms of a military response", Coffman said.
Guam hosts two USA military installations and 6,000 U.S. soldiers - making it an attractive target for the North. The call was filmed for some unusual reason, which led to an odd bit in the beginning when Calvo leads off "as the governor of Guam, representing the people of Guam", like he's delivering expository dialogue. He also boasted about the US' nuclear arsenal on Wednesday before adding that "hopefully we will never have to use" nuclear weapons.
The threats of possible aggression against Guam - often referred to as the "tip of spear" - have become a focal point of debate about the presence of United States military forces on the island.