Trump campaign chairman Paul Manafort insisted no mistakes had been made with the speech and said the issue was “totally blown out of proportion.”

“There were a few words on it, but they’re not words that were unique words,” he told The Associated Press. “Ninety-nine percent of that speech talked about her being an immigrant and love of country and love of family and everything else.”

Mrs. Trump’s star turn at the Republican National Convention Monday night captivated a GOP crowd that had rarely heard from the wife of Donald Trump. The passages in question focused on lessons that Trump’s wife says she learned from her parents and the relevance of their lessons in her experience as a mother.

Manafort told CNN Mrs. Trump was aware of “how her speech was going to be scrutinized” and said any notion that she picked up portions of Mrs. Obama’s convention talk was “just absurd.” He also tried to blame Hillary Clinton.

“I mean, this is, once again, an example of when a woman threatens Hillary Clinton, how she seeks out to demean her and take her down,” Manafort said. “It’s not going to work.”

The White House declined to comment on similarities between the two prime-time speeches, but the issue is likely to arise at the daily White House briefing.

The passages in question came near the beginning of Mrs. Trump’s roughly 10-minute speech. Her address was otherwise distinct from the address that Mrs. Obama gave when then-Sen. Barack Obama was being nominated for president.

In Mrs. Trump’s speech in Cleveland, she said: “From a young age, my parents impressed on me the values that you work hard for what you want in life, that your word is your bond and you do what you say and keep your promise, that you treat people with respect. They taught and showed me values and morals in their daily life.”

In Mrs. Obama’s 2008 speech in Denver, she said: “And Barack and I were raised with so many of the same values: like, you work hard for what you want in life, that your word is your bond, that you do what you say you’re going to do, that you treat people with dignity and respect, even if you don’t know them and even if you don’t agree with them.”

Republican National Committee chairman Reince Priebus said he would “probably” fire his speechwriters if they lifted passages from someone else’s remarks. Priebus told reporters at a Bloomberg breakfast that the controversy was a “distraction” but said he expected the convention to get back on message Tuesday.

Asked about Priebus’ comments, Manafort told the AP, “Frankly, if I knew somebody did it I would fire them too.”

New Jersey Gov. Chris Christie tried to tamp down the controversy, saying “93 percent of the speech is completely different” from the speech Mrs. Obama delivered. Christie said on NBC’s “Today” show that the women “expressed some common thoughts.” He did not explain how he arrived at the 93 percent figure.

Another passage in Mrs. Trump’s speech with notable similarities to Mrs. Obama’s remarks addresses her attempts to instill those values in her son.

“We need to pass those lessons on to the many generations to follow,” Mrs. Trump said. “Because we want our children in this nation to know that the only limit to your achievements is the strength of your dreams and your willingness to work for them.”

In the first lady’s 2008 speech, she said, “Barack and I set out to build lives guided by these values and to pass them onto the next generation, because we want our children — and all children in this nation — to know that the only limit to the height of your achievements is the reach of your dreams and your willingness to work hard for them.”

Trump’s campaign initially responded that Mrs. Trump’s “immigrant experience and love for America shone through in her speech.” The statement didn’t mention Mrs. Obama. “In writing her beautiful speech, Melania’s team of writers took notes on her life’s inspirations, and in some instances included fragments that reflected her own thinking,” Trump spokesman Jason Miller said.

In an interview with NBC News taped ahead of her convention appearance and posted online early Tuesday, Mrs. Trump said of her speech, “I wrote it.” She added that she had “a little help.”