US President Barack Obama has said Republican Donald Trump's claims that the 2016 US presidential election is rigged is "dangerous" and corrosive for democracy.
"When you try to sow the seeds of doubt in people's minds about the legitimacy of our election, that undermines our democracy," Mr Obama said, urging a "big" win for Democrat Hillary Clinton so as to "leave no doubt" about the result.
"When you suggest rigging or fraud without a shred of evidence, when last night at the debate, Trump becomes the first major party nominee in American history to suggest that he will not concede despite losing ... that is not a joking matter."
Yesterday Mr Trump said he would accept a "clear" election result but reserved the right to file a legal challenge, clarifying his stance after he refused to promise he would trust the outcome if he loses on 8 November.
"Of course, I would accept a clear election result, but I would also reserve my right to contest or file a legal challenge in the case of a questionable result," Mr Trump said at a rally in Ohio.
When asked at his final debate with Mrs Clinton if he would accept a losing outcome, Mr Trump said he would "keep you in suspense".
"I'll look at it at the time," Mr Trump said. "What I've seen is so bad."
An angry Mrs Clinton responded with incredulity to the highly controversial charge, saying: "I, for one, am appalled that somebody who is the nominee of one of our two major parties would take that kind of position."
Mrs Clinton said Mr Trump has a pattern of saying competitions and cases he loses are rigged including when he did not win an Emmy for his TV reality show The Apprentice. To which Mr Trump said he should have won the Emmy.
