Gillard backs Clinton in campaign video

Former prime minister Julia Gillard has attacked inept US Republican presidential candidates in an endorsement for Democratic candidate Hillary Clinton.

In the video posted on Clinton's website, Ms Gillard is critical of the way in which Republican presidential candidates make "cheap and easy statements" on foreign policy.

"Hard words often get very ugly reactions," the former Labor leader says.

"And there's a real risk when people are campaigning for office that they use characterisation that is quick and might play in some constituencies back home but does damage that reverberates for years and years."

Ms Gillard says that if she was an American she would want to see the reputation of the USA get stronger rather than be put "at risk because of cheap and easy statements being injected into complex foreign policy debates".

The video features pictures of candidates Donald Trump, Ben Carson and Marco Rubio.

The Republican presidential candidates were widely criticised for their poor performance during a televised debate focusing on foreign policy issues.

Trump has called for Muslims to be banned from entering the US.

Chris Christie said during the debate he would be more trusted by King Hussein of Jordan than President Barack Obama when it comes to fighting Islamic State.

But King Hussein died in 1999.