On the eve of Donald Trump's inauguration, Billionaire investor George Soros said Thursday the US President-elect is "going to fail".

During a speech in Davos, the venue for the World Economic Forum, Soros called Trump a "would-be-dictator", saying he was "gearing up for a trade war".

A trade war would have "a very far reaching effect in Europe and other parts of the world," warned Soros, a supporter of Democratic candidate Hillary Clinton during the 2016 presidential campaign.

The "would-be-dictator ... didn't expect to win," said Soros.

According to Bloomberg Television reports, Soros said "I personally am convinced that (Trump) is going to fail."

He is going to fail "not because of people like me who would like him to fail, but because the ideas that guide him are inherently self-contradictory," Soros said.

The financial markets will "not do very well" due to the uncertainty caused by the Trump administration, Soros further predicted.

"Right now uncertainty is at the peak," Soros said, adding "It's impossible to predict exactly how Trump is going to act."

The United States is holding the quadrennial presidential inauguration ceremony on Friday when Trump will be sworn in as the country's 45th president.

Trump on Thursday nominated former Governor of Georgia Sonny Perdue as Secretary of Agriculture, completing his entire cabinet selection before his inaugural ceremony.