President Barack Obama has lashed out at Donald Trump’s claims that the 2016 election is rigged, calling the suggestions “dangerous” and damaging to 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 on Thursday at a rally in Miami Gardens, Florida, AFP reports.

"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.”

Mr Obama told the rally you can "reject somebody who proves himself unfit to be president every single day in every single way."

The comments come after Mr Trump said he would accept the result of the 2016 election if he wins, as he attempted to clarify remarks he made at the third presidential debate where he said he would keep voters “in suspense” as to his acceptance of the results on 8 November.

Speaking at a rally in Ohio on Thursday, Mr Trump said: "I would like to promise and pledge to all of my voters and supporters and to all of the people of the United States, that I will totally accept the results of this great and historic presidential election - if I win."

He added he would accept "a clear election result", but "reserve my right to contest or file a legal challenge in the case of a questionable result".

Mr Trump's statement, the most provocative in a turbulent debate, made headlines across the country and raised questions about his commitment to a peaceful transition of power, a cornerstone of American democracy.

What did Donald Trump say during the third presidential debate? Show all 9 1 /9 What did Donald Trump say during the third presidential debate? What did Donald Trump say during the third presidential debate? Mr Trump denying claims from a number of women that he sexually assaulted them “This is all fiction, all fictionalised, probably or possibly started by her and her very sleazy campaign. I didn't even apologise to my wife who is sitting right here because I didn't even do anything” Getty What did Donald Trump say during the third presidential debate? Mr Trump claiming the Russian leader had “no respect” for Mrs Clinton “She doesn't like Putin because Putin has outsmarted her every step of the way. He has no respect for her. He has no respect for our President." Getty What did Donald Trump say during the third presidential debate? Mr Trump interrupting Mrs Clinton with one of his most scathing personal attacks yet as she explained her policy on social security “Such a nasty woman” Getty What did Donald Trump say during the third presidential debate? Mr Trump claiming Mrs Clinton shouldn't have been allowed to run for presidency and that the election is rigged “She should never have been allowed to run. She’s guilty of a very very serious crime. She should not be allowed to run. And just in that respect, I say it’s rigged.” Getty What did Donald Trump say during the third presidential debate? Mr Trump voicing his “pro-life” stance during the abortion debate “Based on what she's saying ... you can take the baby and rip the baby out of the womb in the ninth month, on the final day, and that's unacceptable” Getty What did Donald Trump say during the third presidential debate? Mrs Clinton suggesting this is not the first time Mr Trump has claimed results against him have been rigged “There was even a time when Trump didn't get an Emmy for his TV programme three years in a row and he started tweeting that the Emmys were rigged” Getty What did Donald Trump say during the third presidential debate? Mrs Clinton responding to Mr Trump's lewd comments about women “Donald thinks belittling women makes him bigger. He goes after their dignity and self-worth” Getty What did Donald Trump say during the third presidential debate? Mrs Clinton implying Mr Trump is a “puppet” of Russian president Vladimir Putin “He'd rather have a puppet as president of the United States” Getty What did Donald Trump say during the third presidential debate? Mrs Clinton comparing her political experience to Mr Trump's former television role “On the day I was in the situation room monitoring the raid that brought Osama Bin Laden to justice he was hosting the Celebrity Apprentice” Getty

Hillary Clinton also attacked Mr Trump's view on the US democracy - in place for 240 years - calling it "horrifying".

Arizona senator John McCain, who lost the 2008 presidential race to Barack Obama, condemned Mr Trump’s comments. “I had a duty to concede, and I did so without reluctance,“ he said in a statement.

“A concession isn’t just an exercise in graciousness. It is an act of respect for the will of the American people, a respect that is every American leader’s first responsibility.”

Mr Trump was also rebuked by Republican senators Jeff Flake of Arizona and Lindsey Graham of South Carolina, as well as Kelly Ayotte of New Hampshire and Maine governor Paul LePage.

He and his allies have claimed over the last week that there was widespread voter fraud and the election was “rigged” against him, a theme he started months ago, mirroring Bernie Sanders' speeches which claimed the economy and the election was fixed to benefit "those at the top".

He continued to peddle the concept of “Crooked Hillary” at the rally on Thursday and said she should not be able to run for president.