Republican presidential nominee Donald Trump refused to acknowledge making any mistakes on the campaign trail, but said that "it's OK" if he loses because he will simply return to "a very good way of life."

Trump grew defensive Thursday morning when a CNBC host asked whether his reaction to the family of deceased veteran, Army Capt. Humayun Khan, and his controversial statements about Hillary Clinton and the Second Amendment, were errors of his own doing.

"Do you agree with your friend Carl Icahn that you made a mistake?" asked a CNBC host.

"Uh, you'll have to define what a mistake means," Trump replied. "We're not here to talk about that, we're here to talk about economics."

Trump pivoted to blast Hillary Clinton's upcoming "phony speech" about the economy that she will deliver Thursday afternoon. Pressed on Republicans defecting from him as the GOP nominee and criticizing his style, Trump countered that he defeated 17 opponents in the GOP primary and he did not think he made too many errors.

When CNBC pushed back against Trump, he doubled down on his most inflammatory remarks from recent days.

"I want to ask you about the rally last night in Florida that you referenced where you called the president of the United States the founder of ISIS, you said it repeatedly. ... Do you think it's appropriate to call the sitting president of the United States the founder of a terrorist organization that wants to kill Americans?"

"He was the founder of ISIS, absolutely," Trump replied.

The businessman and former reality television star continued, "Why is there something wrong with saying that? Are people complaining that I said he was the founder of ISIS?"

"I'm wondering how you think that's going to play in some battleground states—" the CNBC host replied before Trump interrupted.

"I don't know, I don't know, whatever it is, it is," Trump interjected. "Look all I do is tell the truth, I'm a truth teller."

Trump added, "And if at the end of 90 days, I fall in short because I'm somewhat politically correct, even though I'm supposed to be the smart one and even though I'm supposed to have a lot of good ideas, it's OK. I go back to a very good way of life. It's not what I'm looking to do, I think we're going to have a victory, but we'll see."

Asked about how he intends to close the gap with Clinton, the GOP nominee said he would, "Just keep doing the same thing I'm doing right now."

"At the end it's either going to work or I'm going to have a very, very nice, long vacation," Trump said.

Eighty eight days remain until Election Day.