Donald Trump predicted nearly one year ago that he might make a big apology

Republican presidential candidate Donald Trump hinted last September that he might apologize for some things.

The real-estate mogul briefly pivoted from his usual rhetoric on Thursday during a speech in Charlotte, North Carolina.

Reading from a teleprompter, Trump said "Sometimes in the heat of debate and speaking on a multitude of issues you don't choose the right words or you say the wrong thing ... And I do regret it ... particularly where it may have caused personal pain."

Trump did not highlight any particular incidents that he regrets - and while he is better known for simply leaning into controversies rather than avoiding them, he has previously suggested that he is not above reproach.

In a September 2015 interview on "The Tonight Show" with Jimmy Fallon, Trump quipped that "apologizing is a great thing, but you have to be wrong ... I will absolutely apologize sometime in the hopefully distant future if I'm ever wrong."

For its part, Hillary Clinton's campaign did not buy Trump's mea culpa on Thursday. A statement from the campaign's deputy communications director, Christina Reynolds, called on the billionaire businessman to show some receipts.

"Donald Trump literally started his campaign by insulting people," the statement read, adding that the apology is only "a well-written phrase until he tells us which of his many offensive, bullying and divisive comments he regrets - and changes his tune altogether."