-- Monday's Republican primary debate in Salt Lake City, Utah, has been canceled, according to the Republican National Committee and host Fox News.
"This morning, Donald Trump announced he would not be participating in the debate. Shortly afterward, John Kasich's campaign announced that without Trump at the debate, Kasich would not participate. Ted Cruz has expressed a willingness to debate Trump or Kasich -- or both. But obviously, there needs to be more than one participant. So the Salt Lake City debate is cancelled," Fox News' Michael Clemente wrote in a statement.
Monday's debate at the Salt Palace Convention Center would have been the final GOP debate before the Republican convention in July.
"I was very surprised when I heard that Fox called for a debate," Trump said this morning during an interview on "Fox & Friends." "Nobody told me about it. I won't be there, no."
Instead, Trump will be speaking at the American Israel Public Affairs Committee Conference (AIPAC) in Washington, D.C., on Monday.
When asked whether he would reconsider, Trump stood firm.
"I can't. I have committed to the speech and I've committed to it," Trump said.
He continued: "I wouldn't mind, you know, going to the debate. I think we have had enough of them, I'll be honest with you."
Ohio Gov. John Kasich decided to skip the debate as well after Trump made his decision public. Kasich would have attended if Trump reversed his decision, the Kasich campaign said.
"Donald Trump's decision to scuttle the Salt Lake City debate is disappointing, but not surprisingly...we had hoped to contrast Governor Kasich's positive inclusive approach to problem solving with Trump's campaign of division. If he changes his mind, we will be there," John Weaver, John Kasich's chief strategist, said earlier today.
Sen. Ted Cruz attacked Trump on social media for not committing to the debate, calling him "Ducking Donald."
ABC News' Christopher Donato and Ben Gittleson contributed to this report.