As his poll numbers dive, the Republican presidential hopeful has repeatedly cast doubt on the validity of the election. He said in Ohio that he would "totally" accept the results, pausing before adding "if I win."
Following similar comments in Wednesday night's debate, Trump told a rally on Thursday that he would accept the results of November 8's presidential elections, provided they favored him.
"I will totally accept the results of this great and historic presidential election - if I win," the Republican told supporters. Clarifying his statements a few minutes later, he added "I would accept a clear election result, but would also reserve my right to file a contest or legal challenge in the case of a questionable result."
When asked at the most recent presidential debate if he would concede defeat to Clinton, Trump said "I'll keep you in suspense."
Trump has repeatedly accused both his rival, Democrat Hillary Clinton, and the media of "rigging" the election - although he has not offered any evidence, the allegations often revolve around claims of people participating who should not have a vote.
Kaine: Trump's comments 'surreal'
Critics have argued that Trump's statements, as well as calling on supporters to "monitor" polling places for election fraud, are attempts to subvert the peaceful transfer of power that has been a staple of American political stability.
Hillary Clinton's running mate Tim Kaine slammed the comments from Trump, saying the Republican White House hopeful would defend Russian President Vladimir Putin, but not his own country.
"You will not defend American democracy, but you're trying to defend Vladimir Putin on the stage and you want to be president of the United States?" Kaine asked at a campaign event in North Carolina, adding that he found Trump's comments "surreal."
es/msh (AP, Reuters)