REUTERS/Jay Paul
Donald Trump.
Trump wrote that the network "has just agreed that the debate will be TWO HOURS."
"Fantastic news for all, especially the millions of people who will be watching!" he exclaimed.
CNBC declined to comment to Business Insider, but a Friday CNN report confirmed Trump's claim.
Trump's campaign previously told The New York Times that he would consider withdrawing from the debate if it were three hours long.
"For us it was imperative that the time be changed to 120 minutes," said Trump's campaign manager, Corey Lewandowski.
Retired neurosurgeon Ben Carson reportedly also pushed for a two-hour length, while other candidates were demanding CNBC keep the opening and closing statements. But Trump's demands carry extra force due to his status as both the Republican front-runner and television-ratings magnet.
Trump was furious over the format of the previous Republican debate, hosted by CNN, that dragged three hours long. At the time, critics mocked Trump for losing some of his steam toward the end of the event.
However, Trump argued Thursday that a three-hour debate would simply be unfair to the Republican voters watching the event.
"It's unfair to the viewers. I don't care. I could stand for five hours. I could stand for 10 hours. But it's unfair to the viewers. It's too long," he said in a Fox News interview. "The Democratic debate, if you look at it, that was two hours and it was too long. Everybody was bored at the end. They want to make this much longer than that."