"Tourism, I can tell you this - tourism, you're going to go up like 10-fold with the expenditure of no money so I congratulate you", Mr Trump is heard saying on a speakerphone in a video posted to Facebook by Guam's Governor Eddie Baza Calvo.
A video shows Gov. Eddie Baza Calvo laughing and joking with the president as they discuss everything from the readiness of the USA military to tourism.
Trump's call came as North Korea is threatening an attack on Guam amid escalating tensions over North Korea's continued push to develop nuclear weapons capable of reaching the US mainland.
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Trump continues, "This is between you and I, but you don't talk like they talk, you can't do that, and you can't do that with people like us".
"Mr President, as the Governor of Guam, representative of Guam's people, and as an American citizen, I felt never more safe and confident with you at the helm", the Governor said with a smile.
"They should have had me eight years ago, or at least somebody with my thought process", Trump said. "We've got 95 percent occupancy, and after all this stuff calms down, we're going to have 110 percent occupancy". "I wanted to call you and say hello, how are you?"
The US president told Mr Calvo that Guam - which has a population of 160,000 and is about twice the size of Malta - seemed attractive, telling the governor he had seen images in news reports about the North Korean threat.
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Trump also warned if Kim followed through on plans to strike Guam, the USA response "will be an event the likes of which nobody's seen before".
The New York Times was mocked by social media users on Friday after the paper tweeted out a question asking which was the greater threat to Guam: a nuclear bomb threat from North Korea or climate change?
"I'm glad you're holding the helm sir", Calvo said.
"If an attack warning is issued, take cover as quickly as you can, under concrete structure or below ground if possible", the sheet adds.
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The comments follow reports that the North has mastered a technology needed to strike the United States with a nuclear missile. Fossil tumbled 25.1% after the watch maker said sales continued to weaken, falling short of analysts' estimates.
"You know what, that could happen.it looks so handsome to me", Trump said. "You are safe", the president said.
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