Trump’s language has become increasingly hard-edged since Pyongyang carried out a pair of successful intercontinental ballistic missile tests (ICBM) in July, which put the US mainland in range for the first time.

Pyongyang’s KCNA state news agency reported Wednesday that plans were being drawn up for missile strikes against Guam that could be put into action at “any moment” after Kim gave the order.

Tillerson, who refueled in Guam while flying home from Southeast Asia, said Trump was determined to send an unequivocal message to Kim.

“Because he doesn’t seem to understand diplomatic language,” he said.

The island’s governor Eddie Calvo reassured residents there was currently no threat to the territory, which has a total population of more than 160,000 and houses two US military installations.

In the capital Hagatna, islanders kept their cool.

“It’s not like there’s anything we can do anyway. This is a small island. There’s nowhere to run to,” resident James Cruz said AFP.