New York (CNN Business) NBC News, facing mounting backlash stemming from former "NBC Nightly News" anchor Tom Brokaw 's comments that Hispanics should "work harder at assimilation" into American culture, distanced the network from his "inappropriate" commentary.

"Tom's comments were inaccurate and inappropriate and we're glad he apologized," an NBC spokesperson said Monday.

Also on Monday, an alliance of Latino advocacy groups wrote an open letter to NBC demanding more than just an apology.

"Mr. Brokaw's comments are more than just out-of-touch musings," the letter said. "Mr. Brokaw's comments are part of a legacy of anti-Latino sentiment that is spreading freely in 2019."

The groups called on NBC to improve the diversity of bookings on "Meet the Press;" make a "significant" donation to the National Association of Hispanic Journalists; and produce a series about the Hispanic community in the United States.

Brokaw tweeted Sunday that he regrets the comment he made on "Meet the Press" Sunday.

"I feel terrible a part of my comments on Hispanics offended some members of that proud culture," he said at the beginning of a series of tweets.

The veteran newsman also said he has "worked hard to knock down false stereotypes," and pointed out that he said in his final comment on Sunday's "Meet the Press" that all sides have to work harder.

Criticism erupted after Brokaw, 78, commented on Hispanics and assimilation during Sunday's broadcast of "Meet the Press." He said on the show that his view on assimilation is one he's been sharing "for a long time."

"You know, they ought not to be just codified in their communities but make sure that all their kids are learning to speak English, and that they feel comfortable in the communities," he said during Sunday's segment. "And that's going to take outreach on both sides [Republican and Democrat], frankly."

Although he did not issue a formal apology at first, Brokaw emerged again later in the night with another series of tweets in which he said that he is "truly sorry" for his remarks, which he acknowledged were "offensive to many." He also thanked fellow panelist and "PBS Newshour" correspondent Yamiche Alcindor for her comments during the segment, saying she's a "wonderful colleague and an important voice."

"I never intended to disparage any segment of our rich, diverse society which defines who we are," Brokaw said.

During the segment, Alcindor challenged some of Brokaw's comments.

"We also need to adjust what we think of as America," she said. "You're talking about assimilation. I grew up in Miami, where people speak Spanish, but their kids speak English. And the idea that we think Americans can only speak English, as if Spanish and other languages wasn't always part of America, is, in some ways, troubling."

Tom Brokaw, one of America's best known journalists, has won 11 Emmy awards during his career.

'A punch in the gut'

"It really was a punch in the gut to a lot of people," he said. "It was not only factually incorrect, it was also xenophobia in action."

Speaking on CNN's "Newsroom" later in the day, liberal commentator Maria Cardona said that she loves Brokaw, but that "he's a little out of touch."

"I'll give him a pass because he's probably not up to speed as to where things are today and age, especially with young Latinos in this country," she said. She insisted that "Latinos absolutely assimilate."

The National Association of Hispanic Journalists said in a statement late Sunday that it found both Brokaw's initial comments and his Twitter response reprehensive.

Hugo Balta, the organization's president and a senior producer at MSNBC, said that assimilation means "denying one culture for another."

"Hispanics are no less American for embracing their country of origin or that of their ancestors ... being bicultural and bilingual is a strength in an increasingly multi-ethnic, multilingual society," he said.

After reading Brokaw's response to the controversy, conservative commentator Erick Erickson weighed in on Twitter. He said Brokaw's comments on the "Meet the Press" were not something "that anyone needs to apologize for making. They're truths people don't want to hear."

Erickson's tweet was a preview of how this debate is likely to unfold — pitting prominent conservatives and liberals against one another. Sure enough, some Fox News commentators stood up for Brokaw on Monday.

But a portion of Brokaw's remarks on "Meet the Press" also stoked anger among Republicans.

Before his comments about assimilation, he said that many Republicans perceive the growth of the Hispanic population in the United States to be helping Democrats.

"Also," he said, "I hear when I push people a little harder is, 'I don't know whether I want brown grandbabies.' That's also a part of it."

His talk of racial animus on the right spurred objections from Republicans like Texas Land Commissioner George P. Bush, whose mother is Mexican-American.

"With all due respect @Tombrokaw," Bush tweeted on Monday, "I am one of those 'little brown ones' and can assure you that my grandparents conveyed to me that they loved and were proud of me before they passed."

Correction: An earlier version of this story misspelled Hugo Balta's name.