HAGATNA, Guam (AFP) - Guam's leader said on Monday (Aug 14) that "sometimes a bully can only be stopped with a punch in the nose", in a spirited defence of President Donald Trump's rhetoric against North Korea which has the island in its crosshairs.

While Trump's critics accuse him of inflaming tensions with Pyongyang, Guam governor Eddie Calvo said he was grateful the US leader was taking a strong stance against North Korean threats against his Pacific homeland.

"Everyone who grew up in the schoolyard in elementary school, we understand a bully," Calvo told AFP.

"(North Korean leader) Kim Jong Un is a bully with some very strong weapons... a bully has to be countered very strongly."

Calvo, a Republican, said Trump was being unfairly criticised over his handling of the North Korea crisis, which escalated when Pyongyang announced plans to launch missiles toward Guam in a "crucial warning".

He said North Korea had threatened Guam - a US territory which hosts two large military bases and is home to more than 6,000 military personnel - at least three times since 2013.

He said previous presidents had also used strong words to warn off Pyongyang, pointing out Barack Obama said last year that "we could, obviously, destroy North Korea with our arsenals".

"One president (Obama) said it one way, cool and calmly with a period... the other said fire and fury with an exclamation point, but it still leads to the same message," Calvo said.

He rejected suggestions that Trump and the North Korean dictator were as bad as each other when it came to the sabre-rattling playing out in the western Pacific.

"Well there's only one guy that has vaporised into a red mist his uncle or a general because he fell asleep in a meeting with an anti-aircraft gun, that's Kim Jong Un," he said.

"There's only one guy that's killed his brother with one of the most toxic nerve agents ever created, that's Kim Jong Un."