After saying he may not accept the result of the US election during the third presidential debate, Republican candidate Donald Trump now says he will accept it 'if I win'.
He appeared at a rally in Delaware, Ohio, speaking for the first time since the third televised debate with Democratic opponent Hillary Clinton.
He told the Ohio audience that the election was posing questions about "the fairness of our country".
"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 said, grinning.
He also said: "I will accept a clear election result, but I will also reserve my right to contest and file a legal challenge in the case of a questionable result."
Mr Trump has repeatedly claimed that the election is "rigged" against him, and when asked during yesterday's debate by moderator Chris Wallace if he would accept losing to Mrs Clinton, Mr Trump said he would "keep you in suspense".
He has been heavily criticised for suggesting that he might not accept the election result.
Former Republican presidential candidate Senator John McCain, who lost to Barack Obama eight years ago, made a statement about Mr Trump's approach.
"I didn't like the outcome of the 2008 election. But I had a duty to concede, and I did so without reluctance," Mr McCain said.
"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."
After the debate, Mr Trump's campaign manager Kellyanne Conway insisted he had meant he would not concede until the "results are actually known".
Polls suggest Mrs Clinton is ahead nationally and in key battleground states.
'Lock her up'
At the Ohio rally, Mr Trump also reiterated a claim he made during the debate against Mrs Clinton and Mr Obama, who he said were responsible for inciting violence at a Chicago rally earlier this year.
The crowd erupted into cheers of "lock her up".
Mr Trump has trailed Mrs Clinton in the polls after facing damaging fallout over a video that emerged of him making obscene remarks about groping women.
Another accuser came forward a few hours after the third debate, saying Mr Trump - who she had not met before - had approached her and touched her breast outside the US Open tennis tournament in New York in 1998.
When asked to address the allegations made against him by several women in the wake of the video, Mr Trump said the claims had been "largely debunked".
The two candidates are scheduled to appear at a charity dinner on Thursday night in New York.