NEW YORK (CNNMoney) -- The war between Donald Trump and Fox News is back on.
On Wednesday, Trump tweeted that he would be boycotting Fox News because the network had treated him "very unfairly." But a Fox News spokesperson told CNN that Trump only made that claim after Fox canceled his scheduled appearance on "The O'Reilly Factor."
"At 11:45 a.m. today, we canceled Donald Trump's scheduled appearance on The O'Reilly Factor on Thursday, which resulted in Mr. Trump's subsequent tweet about his 'boycott' of Fox News," the spokesperson wrote in an email.
Trump tweeted shortly after noon, "Fox News has been treating me very unfairly & I have therefore decided that I won't be doing any more Fox shows for the foreseeable future."
Fox News declined to specify why it had canceled Trump's appearance, but it came after a series of tweets Trump wrote Monday criticizing "The O'Reilly Factor" and anchor Megyn Kelly.
"When coverage doesn't go his way, he engages in personal attacks on our anchors and hosts, which has grown stale and tiresome," the Fox News spokesperson said. "He doesn't seem to grasp that candidates telling journalists what to ask is not how the media works in this country."
The network also criticized the media for its initial portrayal of Trump's boycott announcement. "The press predictably jumped to cover his tweet, creating yet another distraction from any real issues that Mr. Trump might be questioned about," the spokesperson said.
Trump's office replied with a statement saying, "Mr. Trump stands by his statement made earlier today."
Fox and Trump were getting along well enough earlier this week when Trump was booked to appear this Thursday night on "The O'Reilly Factor." Bill O'Reilly even promoted the upcoming Trump interview while appearing Monday night on "Jimmy Kimmel Live," which was taped Monday evening.
By Monday night, however, Trump was unhappily watching O'Reilly's show and began a series of angry tweets.
"I am having a really hard time watching Fox News," Trump tweeted, and complained that O'Reilly's show had been "very negative to me" because its guests were all "Trump haters."
Trump's Twitter storm continued into Tuesday when he resumed his attack on Kelly, who has drawn Trump's fire since her grilling of the candidate during the first GOP debate.
"She is the worst - all anti-Trump!" Trump tweeted during her program. "Terrible show."
On Wednesday, Fox says it canceled Trump's O'Reilly appearance, and Trump announced his Fox boycott.
Trump had previously threatened to boycott Fox News in the wake of the first Republican primary debate six weeks ago on the grounds that the network's moderators -- particularly Kelly -- had been unfair to him. The two parties reached detente after Fox News Chairman and CEO Roger Ailes called Trump to assure him that he would be treated fairly.
But the truce was an exceedingly fragile one — and now it's over.
Trump has yet to specify exactly what he objects to in the network's coverage.
On Wednesday, a Fox News source argued that Trump was antagonizing Fox in order to create controversy and draw attention to himself because of his decline in the polls.
For Fox News, the boycott means it will be cut off from the Trump ratings machine, which is proven to boost ratings for any network. By the same token, Trump will miss out on access to the millions of viewers who tune into Fox News every night for coverage of the 2016 race.
Trump, who gave a relatively subdued performance at the Sept. 16 GOP debate, is down 8 points in the latest CNN/ORC national poll. Meanwhile, rivals like Carly Fiorina and Ben Carson have been on the rise, and commanding more and more media attention.