Donald Trump Won't Run a Third-Party Campaign: 'I Have Signed the Pledge'

He made the announcement from the Trump Tower.

— -- Donald Trump is all in.

The Republican presidential frontrunner said he will commit to supporting the eventual Republican nominee, ruling out a third-party bid for the Oval Office that would likely draw general election voters away from the Republican nominee.

“What did I get from signing the pledge? Absolutely nothing," Trump said. "Just the assurance that I’ll be treated fairly.”

It's not clear whether there would be legal or other ramifications for breaking the pledge or how they would be enforced.

As Trump held the pledge up for the crowd, reporters pointed out that he had listed "August 3" as the date instead of "September 3." "We'll change it," Trump said.

ABC News has confirmed that roughly half the Republican field has already signed or plans to sign the RNC’s pledge.

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