Donald Trump has declined to say how much of a sore loser he would be were Hillary Clinton to triumph in the US election next month.
The Republican candidate has refused to commit to accepting the result of the election, which he has suggested could be rigged.
“What I'm saying is that I will tell you at the time. I'll keep you in suspense. Okay?” he told the moderator of the last of three debates with his rival, Hillary Clinton.
Read more: Is Trump now too far behind to win?
Democrat Clinton described Trump’s comment to moderator Chris Wallace as “horrifying”.
“That is not the way our democracy works,” Clinton said in the debate.
“We've been around for 240 years. We've had free and fair elections. We've accepted the outcomes when we may not have liked them.
“And that is what must be expected of anyone standing on a debate stage during a general election.”
Yesterday, current President Barack Obama told Trump to “stop whining” about the possibility that the election could be rigged, saying his arguments were “based on no facts”.