The remarks, which she made during an interview with the Australian Broadcasting Corporation's "Four Seasons" programme, follow a warning she issued during the presidential campaign — that Mr Trump was the most dangerous White House candidate ever to make a leadership bid.
Asked by journalist Sarah Ferguson whether Mr Trump was the most dangerous President the US had ever had, she said: "I think he is, because he is impulsive, he lacks self-control, he is totally consumed with how he is viewed, with how people think of him. He is vindictive."
When questioned about whether Australia should be worried about the Republican inhabiting the White House, she said: "I think the whole world should be concerned."
Earlier this month the former Secretary of State spoke forcefully in favour of stricter gun control following a massacre in Las Vegas, which killed 58 people and injured hundreds more.
She said: “Our grief isn't enough. We can and must put politics aside, stand up to the NRA [National Rifle Association], and work together to try to stop this from happening again."
Mr Trump was elected with the endorsement of the NRA, and repeatedly said the solution to mass shootings was having more citizens with firearms. The NRA ended up spending more that $30m (£22m) on Mr Trump's presidential bid.
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