MARSHALLTOWN, Iowa -- Republican Donald Trump on Tuesday bowed out of the final Republican presidential debate before the leadoff Iowa caucuses, saying Fox News moderator Megyn Kelly is "a lightweight."

With 48 hours before the faceoff, campaign manager Corey Lewandowski confirmed Trump's decision Tuesday evening after a news conference in which Trump lashed out at Kelly and said she'd been "toying" with him.

"He will not be participating in the Fox News debate Thursday," Lewandowski said after the news conference.

Trump, who called his decision "pretty close to irrevocable" in the news conference, said he'd hold an Iowa event the same time as the debate to raise money for wounded veterans. Iowa hosts the nation's opening presidential primary contest Monday.

"With me, they're dealing with somebody that's a little bit different. They can't toy with me like they toy with everybody else," he said. "Let them have their debate, and let's see how they do with the ratings."

He added, "Why do I have to make Fox rich?"

The Republican National Committee said the decision was up to Trump.

"Obviously, we would love all of the candidates to participate but each campaign ultimately makes their own decision what's it their best interest," RNC chief strategist Sean Spicer said.

Trump had suggested he might skip the Fox debate earlier in the day, drawing a sarcastic statement from the television network "the Ayatollah and Putin both intend to treat Donald Trump unfairly when they meet with him if he becomes president."

"A nefarious source tells us that Trump has his own secret plan to replace the Cabinet with his Twitter followers to see if he should even go to those meetings," the Fox statement said.

A Fox spokesman did not respond to Trump's decision.

Also Tuesday, Trump broke from his reputation as a flame-throwing outsider, highlighting his willingness to work with Democrats in Congress as part of a closing argument with a bipartisan tone.

Trump's promise to get things done in Washington is a direct contrast to leading GOP rival Ted Cruz, the Texas senator whose brief Washington career has been defined in part by his inability to get along with his own party.

"I don't think he'll get anything through Congress because everybody hates him," Trump said of Cruz Tuesday on MSNBC's "Morning Joe."

Trump claimed to have good relationships with such top congressional Democrats as Nancy Pelosi and Chuck Schumer, predicting he could get things done in a way Cruz could not.

"Ted Cruz lies. He is a liar. That's why nobody likes him," Trump said. "That's why he stands on the middle of the Senate floor and can't make a deal with anybody. ... And you know, there's something to say about having a little bit of ability to get other people to do things."