The network said it would no longer air the annual Miss USA and Miss Universe pageants, which had been a joint venture between the company and Trump. Miss USA has aired on NBC since 2003, and this year's edition was set for July 12.
"At NBC, respect and dignity for all people are cornerstones of our values," NBC said in a statement.
Trump's reply: a "weak" NBC should prepare to meet him in court.
NBC's action comes less than a week after Univision similarly decided to ditch Trump and the pageants. Trump has also been a fixture on NBC as host of "The Apprentice" and its celebrity offshoot, and an agreement that he would no longer be on the show predated the current controversy. The network said Monday that it and producer Mark Burnett are exploring ways to continue "Celebrity Apprentice" sans Trump.
Trump said he anticipated losing the business relationship and that he's not apologizing for his statements because they "were correct."
"Whatever they want to do is OK with me," Trump told reporters in Chicago after a campaign speech to civic leaders.
But in a statement issued by his company in New York, Trump said "NBC is weak, and like everybody else is trying to be politically correct. That is why our country is in serious trouble."
He said he'd consider suing, as he plans to do with Univision. He also took a shot at NBC's decision to demote, but not fire, news anchor Brian Williams for telling false stories about some of the reporting he was involved in.
"They will stand behind lying Brian Williams, but won't stand behind people that tell it like it is, as unpleasant as that may be," he said.
During his presidential kickoff speech, Trump said Mexican immigrants are "bringing drugs, they're bringing crime, they're rapists and some, I assume, are good people." He called for building a wall along the southern border of the United States. Trump later said that his remarks were directed at U.S. policymakers, not the Mexican government or its people.
The National Hispanic Leadership Agenda, a group of 39 Latino advocacy organizations, had called on NBC to get out of business with Trump. Similarly, a petition urging the same thing on the Change.org website had gathered more than 218,000 signatures.
Dozens of protesters — from immigrant and Latino rights groups — waited outside of a downtown Chicago restaurant where Trump spoke. Their chats included "No more hate!"
Maritza Vaca, with the Chicago-based Accion Hispano, said immigrants have rights and was upset by Trump's comments.
"It is racism," she said. "For him to be running for president is ridiculous."
NBC said it is still determining what it will air in place of the pageant next month.