Republican presidential hopeful Donald Trump retweeted a quote by Italian fascist dictator Benito Mussolini. The quote by the dictator was originally tweeted by a spoof account, ilduce2016, which uses a picture of Trump's face superimposed on that of Mussolini, who was known as Il Duce in Italy.

"It is better to live one day as a lion than 100 years as a sheep," says the quote.

The quote was attributed to Mussolini by Time magazine in 1943. It resembles an earlier quote by 18th century Indian soldier and poet Tipu Sultan, who said "To live like a lion for a day is far better than to live for a hundred years like a jackal."

This is not Trump's first Twitter gaffe. He has previously retweeted a tweet by a man who was revealed to be a white nationalist and he was tricked into retweeting a picture of serial killers Fred and Rose West, by a man claiming to be their bereaved son.

Trump deleted both of the retweets.

'Ku Klux Klan who?' asks Trump

Trump has campaigned on an anti-immigrant, anti-Islam platform, pledging to make Mexico build a wall to prevent immigrants entering the US, and to bar Muslims entering the US temporarily in response to the terror threat from jihadist group Isis.

This week, two former Mexican presidents compared the billionaire to Nazi dictator Adolf Hitler. Speaking at an event in Mexico City, Felipe Calderón said: "He is acting and speaking out against immigrants that have a different skin color than he does, it is frankly racist and [he is] exploiting feelings like Hitler did in his time."

On Saturday, Jean Marie Le Pen, founder of the French far-right Front National party endorsed Trump, the day after the Ku Klux Klan leader David Duke announced his support for him. Later that day, during an interview with CNN's Jake Tapper Trump refused to condemn Duke's endorsement, telling the TV reporter, "I don't know anything about David Duke.

"Because I know nothing about David Duke, I know nothing about white supremacists," Trump continued. "And so, you are asking me a question that I'm supposed to be talking about people that I know nothing about."

When Tapper asked whether Trump would "unequivocally" condemn the 150-year-old racist organisation

"I don't know what group you're talking about. You wouldn't want me to condemn a group that I know nothing about. I'd have to look. If you would send me a list of the groups, I will do research on them, and certainly I would disavow if I thought that there was something wrong."

Trump's refusal to condemn the KKK is leading to more criticism of the candidate. Hunter Walker, a correspondent for Yahoo News, described him as "the white supremacist candidate".

Trump's victories in early primaries have made him the favourite to be nominated as Republican presidential candidate. On Saturday, he also received the backing of moderate New Jersey governor Chris Christie.