Australian Foreign Minister Kevin Rudd on Tuesday urged the world not to be lured into a false sense of security by North Korea, warning its nuclear weapons drive could become "our worst nightmare".

The North abandoned six-nation talks in April 2009, a month before staging a second nuclear test which brought worldwide condemnation and fresh United Nations sanctions.

Now all sides say they want to start talking again, especially after Pyongyang's disclosure last November of a uranium enrichment programme (UEP) which could give it a second way to make atomic weapons.

Rudd, Australia's former prime minister, urged caution.

"Make no mistake, the North Korean regime is armed and dangerous," he said in an opinion piece for Sydney's Daily Telegraph.

"It has a long history of brinkmanship and has shown that it is prepared to lash out. A cruel totalitarian state, it has no regard for the welfare of its people, much less world opinion."

He said the world should not be fooled by the dire state of the country's economy, with aid groups warning this week that hunger was worsening and could develop into a major crisis next year.

"Let's be clear, the regime in Pyongyang is dangerous. Its behaviour is often unpredictable. But one thing about it we can predict is it being hell-bent on building a nuclear arsenal," he said.

Of particular concern to Australia was the regime's development of new missiles with a much longer range.

Rudd cited the Taepodong 2, which he said could travel as far as 9,000 kilometres (5,580 miles), bringing it within reach of northern Australia as well as the United States.

"North Korea has left no one in any doubt about its determination to eventually field intercontinental ballistic missiles and to miniaturise nuclear bombs so that their missiles can carry them, as difficult a challenge as this is," he said.

Rudd called for a tightening of sanctions against the North Korean leadership, and for its weapons programmes to be countered "in every practical way that we can".

"North Korea is not an abstract threat. It is real. It is worsening. And it could prove to be our worst nightmare," he said.