Presidential candidate Donald Trump visits his Scottish golf course, Turnberry, on July 30, 2015, in Ayr, Scotland. (Jeff J Mitchell/Getty Images)

Republican presidential candidate Donald Trump took an uncharacteristic approach leading up to the first GOP debate, to be held this week, playing down expectations about his performance and saying that he is "highly unlikely" to attack his opponents first.

Making the rounds Sunday on political talk shows, Trump said he is unsure how he will do in his first public debate.

"I'm not a debater. These politicians — I always say, they're all talk, no action. They debate all the time. ... We'll see what happens. Who knows?" Trump said on ABC's "This Week." He added: "I don't think I'm going to be throwing punches. I'm not looking to attack them."

When asked about criticisms he has leveled at competitors, Trump said he had made his comments as a “counterpunch."

"I think I'm a nice person, I really do," he said on NBC’s "Meet the Press." "I’d like to discuss the issues. I’m not looking to take anybody out or be nasty to anybody."

Trump also said he may consider a third-party run, despite a request by Republican National Committee Chairman Reince Priebus for GOP candidates to pledge not to run as third-party candidates if they do not win the nomination. Asked whether he would take the pledge, Trump said it depends on whether he is "treated fairly" by the Republican Party.

"If I'm treated fairly by the Republican Party, I would have no interest in doing that. If I'm not treated fairly by the Republican Party, I very well might consider that. And I would certainly not give that up," Trump said on "This Week."

Several GOP candidates stood by their criticisms of Trump in interviews Sunday. Sen. Rand Paul (R-Ky.), who last week called Trump’s surge a “temporary sort of loss of sanity,” said on CNN’s “State of the Union” that although Trump represents “a vein of anger” toward Washington, “there's also going to be a serious debate, ultimately, starting this week, in the presidential debates, about who has the ideas that would fix the country.”

“I'll challenge Donald Trump. … I'm going to clearly push back, and I'm going to push back hard,” former Texas governor Rick Perry said on “Fox News Sunday,” doubling down on his swipes at Trump.

Meanwhile, Ohio Gov. John Kasich took the opposite approach in his “Fox News Sunday” interview, distancing himself from a tweet by his top political strategist John Weaver.

https://twitter.com/jwgop/status/625810551243825152

“He won't be sending any more tweets like that,” Kasich said. “That's not the way we operate.… We don't appreciate stuff like that. I don't think you'll see any more of that.”