Donald Trump
Donald TrumpReuters

Billionaire Donald Trump announced on Thursday he has signed a GOP pledge not to run as an independent in 2016, after a personal appeal from the Republican Party chairman, Fox News reports.

"I have signed the pledge," Trump said, holding it up.

The decision by the Republican presidential front-runner helps ease concerns among party leadership that an outside Trump bid, should he not win the nomination, could threaten the party's chances in the general election by peeling off votes.

According to Fox News, the party began circulating the pledge to virtually all the Republican campaigns earlier this week, but Trump was the obvious concern. He had been the only one who did not raise his hand when the 10 top-polling candidates were asked at last month's Fox News debate whether they'd commit not to mount an independent White House bid.

Trump, after meeting Thursday with party boss Reince Priebus, said the chairman has been "extremely fair."

"I just wanted fairness from the Republican Party," he was quoted by Fox News as having said. After holding up the pledge, he added, "I will be totally pledging my allegiance to the Republican Party, and the conservative principles for which it stands."

Trump said he got nothing in return, and sees no circumstances under which he would "tear up that pledge."

Several other candidates already have made a similar commitment, the report noted. New Jersey Gov. Chris Christie signed the pledge during an appearance Thursday on Fox News.

Commitments also came in from the campaigns of Ohio Gov. John Kasich; former New York Gov. George Pataki; former Florida Gov. Jeb Bush; former HP CEO Carly Fiorina; retired neurosurgeon Ben Carson; Wisconsin Gov. Scott Walker; former Arkansas Gov. Mike Huckabee; and former Texas Gov. Rick Perry.

So far, Trump’s campaign has been an unconventional one. Last week, he decided to put rumors to rest and prove that his hair is, in fact, his own.

At a rally in South Carolina, an irate Trump responded to a question regarding his coiffed locks with dramatic action, saying, "I don't wear a toupee, it's my hair, I swear. We are going to settle this."

In a surprising and theatrical move, he called on a woman from the audience to come up on stage and silence his hair critics.

He previously publicly gave out the phone number of South Carolina Senator Lindsey Graham, another Republican candidate,       after Graham said Trump is a "wrecking ball" who has put the Republican Party's future on the line. Those comments came in response to Trump’s controversial remarks about Mexican immigrants.

Trump in one debate also criticized the American government and flat out referred to it as “stupid”.