North Korea on Thursday mocked US President Donald Trump by calling him someone “bereft of reason” even as it plans to strike the US territory of Guam.

The scheme to target the island, a key US military stronghold, was intended to “signal a crucial warning” as “only absolute force” would have an effect on the US leader, the North said.

The declaration came after Trump boasted on Twitter that America’s nuclear arsenal was “far stronger and more powerful than ever before”.

Earlier, Trump stunned the world with a bold-faced message to leader Kim Jong-Un that appeared to borrow from Pyongyang’s own rhetorical arsenal, saying the North faced “fire and fury like the world has never seen”.

The war of words over Pyongyang’s nuclear and missile programmes is raising fears of a miscalculation that could lead to catastrophic consequences on the Korean peninsula and beyond.

Last month the North carried out two successful tests of an intercontinental ballistic missile, bringing much of the US mainland within its range.

“Sound dialogue is not possible with such a guy bereft of reason,” the North Korean military said in a statement.

It added that the military would complete the Guam plan by mid-August and submit it to Kim Jong-Un for consideration.