CNBC has given in to Donald Trump's demands and will limit its Oct. 28 Republican primary debate to two hours.

Trump tweeted the news early Friday:

CNN, citing a source with knowledge of the decision,  confirmed Trump's announcement, reporting that the Republican National Committee was contacting campaigns with the news Friday morning.

Trump and candidate Ben Carson, the two leading Republican presidential contenders, on Thursday had threatened to pull out of the third GOP debate in Coloradoin a dispute with CNBC and the RNC over the length of the debate and other rules.

Trump took to Twitter after a conference call Thursday afternoon between RNC officials and top advisers to the candidates erupted into chaos over the issues, Politico reports.

Both Trump and Carson were particularly concerned about the debate's length and whether candidates would be allowed to make opening and closing statements.

The New York real estate magnate posted these tweets:

Trump later Thursday did not rule out appearing, even if the debate did extend beyond two hours.

"I don't care. I can stand for five hours," he told Greta Van Susteren on Fox News. "I can stand for 10 hours. But it's unfair to the viewers. It's too long.

"They have sold out all their commercials and want to increase it by an hour," Trump said of CNBC. "Now, they want to make this an extra hour.

"I think it's unfair to the viewers because it's too much. It's too much to watch — and they are doing it because they want to make more money."

The Carson camp fired off a letter to CNBC Washington Bureau Chief Matthew Cuddy on behalf of both campaigns earlier Thursday. The third debate will be held on Oct. 28 at the University of Colorado-Boulder. 

"Mr. Trump and Dr. Carson do agree to a 120 minute debate that includes commercial breaks and opening and closing statements," the campaign said in the letter, a copy of which was provided to Newsmax. "Mr. Trump and Dr. Carson do not, and will not, agree to appear at a debate that is more than 120 minutes long including commercials breaks.

"Further, the debate must include opening and closing statements from all the candidates," the letter said.

The Carson letter stated that CNBC outlined a two-hour debate format, plus commercials, and without the statements. The objective was "reiterated" in a conference call Wednesday with the campaign staffs.

"To be clear, neither of our campaigns agreed to either the length you propose or your ban on opening or closing statements," the document said. "In fact, neither of our campaigns were even consulted.

"Neither of those conditions are acceptable," the letter continued. "Neither Mr. Trump or Dr. Carson will participate in your debate if it is longer than 120 minutes including commercials and does not include opening and closing statements."

Hope Hicks, a Trump spokeswoman, did not respond to a Newsmax query seeking comment.

"The criteria that was outlined by CNBC was never discussed with any of the candidates or the campaigns," Corey Lewandowski, Trump's campaign manager, told The New York Times. "So what CNBC did was send out a memo and said, 'Here's the criteria as you have approved them' and that went out to all the campaigns.

"We said we never agreed to this criteria," Lewandowski said.

Brian Steel, a CNBC spokesman, told The Hill that the network typically eschewed opening statements "to allow more time to address the critical issues that matter most."

"We started a dialogue yesterday with all of the campaigns involved and we will certainly take the candidates' views on the format into consideration as we finalize the debate structure," Steel said in a statement.

In the Thursday conference call reported by Politico, Lewandowski said that if the debate moved beyond two hours, even with commercials, and excluded the statements, Trump might not participate.

Three sources spoke to Politico about the 29-minute conference call, which was hastily arranged by RNC officials after the campaigns complained the previous day.

The call was led by two top RNC officials, Katie Walsh and Sean Spicer.

They began by telling the campaigns that RNC Chairman Reince Priebus had discussed the statements' issue with CNBC — and that he wanted to learn what each candidate's "red line" was on the terms, Politico reports.

Jason Miller, a strategist for Texas Sen. Ted Cruz, said that the campaign would consider not participating if opening and closing statements were not allowed.

Chris LaCivita, an aide to Kentucky Sen. Rand Paul, then said, "If we don't have opening and closing statements, CNBC can go f--- themselves," Politico reports.

Lewandowski spoke again, followed by Beth Hansen, campaign manager for Ohio Gov. John Kasich.

She called the conference call a "debacle," according to the report.

Sarah Huckabee Sanders, representing former Arkansas Gov. Mike Huckabee, said that she was concerned that not all candidates would have equal time during the debate.

But Terry Sullivan, campaign manager for Florida Sen. Marco Rubio, said that the candidate would be at the debate — "hell or high water" — and that he agreed that all participants should be allowed to make the statements, Politico reports.

Peter Flaherty, an adviser to former Florida Gov. Jeb Bush, voiced similar concerns.

Meanwhile, the manager for New Jersey Gov. Chris Christie's campaign, Ken McKay, said that he was concerned about stating his position on an open conference call, according to the report.

Walsh, the RNC's chief of staff, then tried to end the call. But Christian Ferry, a top adviser to South Carolina Sen. Lindsey Graham, asked whether any candidates at the lower end of the polling would be allowed in if others pulled out.

Graham has been relegated to the lower-tier debates.

But former Hewlett-Packard CEO Carly Fiorina attacked Trump and Carson, saying that she wanted a longer debate.

She moved up to the main debate after a strong appearance in the first "happy hour" debate.

"Apparently, they're worried about answering questions for three hours," Fiorina told Megyn Kelly on Fox News. "We have 10 candidates on the stage. I don't think three hours is a long time. 

"I think the American people really like them," she added. "And we ought to stand and answer as many questions as we can."

Fiorina contrasted Trump and Carson's "outsider" status with their demands for the opening and closing remarks.

"Prepared statements are what politicians do," she told Kelly. "You're two outsiders.

"Honestly, they sound a lot like politicians tonight to me."

Former New York Gov. George Pataki, also an undercard participant, used Twitter to slam the GOP front-runners: