A letter from North Korea to nations including Australia urging them to distance themselves from the United States has been described by Malcolm Turnbull as "a rant about how bad Donald Trump is".

Key points: The letter comes after Donald Trump threatened to "totally destroy" North Korea during a recent UN speech

The letter comes after Donald Trump threatened to "totally destroy" North Korea during a recent UN speech It says any attempt by the US to destroy it could lead to a "horrible nuclear disaster"

It says any attempt by the US to destroy it could lead to a "horrible nuclear disaster" It is believed the letter was sent to several parliaments around the world

North Korea wrote an open letter to parliaments around the world, a month after US President Donald Trump spoke at the United Nations General Assembly and called North Korean leader Kim Jong-un a "rocket man on a suicide mission for himself and his regime".

The letter, from the Foreign Affairs Committee of the rogue state's Supreme People's Assembly, described Pyongyang as a fully-fledged nuclear power and said any attempt by the United States to destroy it would be a big miscalculation and could lead to a "horrible nuclear disaster".

"Trump threatened to totally destroy the DPRK, a dignified independent and sovereign state and a nuclear power. It is an extreme act of threatening to totally destroy the whole world," it said.

Mr Turnbull dismissed the letter as "basically a rant" and said it was consistent with North Korea's "ranting and complaining about Donald Trump".

"The fact of the matter is that North Korea is the one that is in breach of UN Security Council resolutions. It is North Korea that is threatening to fire nuclear missiles at Japan and South Korea and the United States," the PM told Melbourne radio 3AW.

"It is North Korea that is threatening the stability of the world.

"That is the regime that has to return to its senses and stop this reckless conduct."

Australia is one of the recipients of the letter, but the Prime Minister said it did not say anything specific about Australia.

"They have sent it to a lot of other countries, like a circular letter," he said.

Foreign Affairs Minister Julie Bishop said the letter was an unprecedented step from North Korea and called it a positive sign.

"I see it as evidence that the collective strategy of imposing maximum diplomatic and economic pressure though sanctions on North Korea is working," Ms Bishop said.

"This is a response to the pressure that Australia, the United States, China, Japan, South Korea and others are putting on North Korea so that it will refrain from its current conduct of provocative and threatening behaviour and that it will be compelled back to the negotiating table.

"I think this shows they are feeling desperate, feeling isolated, trying to demonise the US, trying to divide the international community."

While she said it was a positive sign, the language in the North Korean letter continued the regime's recent tone about the United States leader.

It called for "sharp vigilance against the heinous and reckless moves of the Trump administration trying to drive the world into a horrible nuclear disaster".

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