Dana Perino, a former White House secretary under George W Bush, defended Mr Trump’s original statements and argued that he “didn’t make them on live television at five o’clock”.
Ms Perino was referring to a number of the US president's controversial remarks quoted by Ms Omar, including the "grab 'em by the p****" line he said in an interview with Access Hollywood in 2005.
Ms Omar also quoted Mr Trump reportedly saying last year that people were coming to the US from "s***hole countries".
It came after the US president tweeted at the weekend that some Democratic congresswomen should “go back and help fix the totally broken and crime infested places from which they came”.
While the US president did not name the targets of his attack, the context of his tweet made it clear it was aimed at a group of four progressive Democratic women of colour known as “the squad”.
Ms Omar claimed that the US president’s racist attacks were a “distraction” from more important issues and sought to divide Americans.
"This is a president who has ultimately violated the very value our country aspires to uphold," she said.
"To distract from that, he is launching a blatantly racist attack on four duly-elected members of the United States House of Representatives, all of whom are women of colour."
Mr Omar, who was falsely accused by Mr Trump of being both antisemitic and a supporter of Al Qaeda, said the US president had adopted the agenda of white nationalists.
"This is a president who has said 'grab women by the p****,'" she added. "This is a president who has called black athletes 'sons of b****es'. This is a president who has called people who come from black and brown countries 'sh**holes.' This is a president who has equated neo-Nazis with those who protest against them in Charlottesville."
However, in a discussion of the congresswomen’s impassioned rebuke of the US president on Fox News, pundit Ms Perino said: “Can we also mention the profanity?”
In response, one of Ms Perino’s co-hosts, said: “They can argue, well that’s what Trump said. So I’m going to say it.”
“But he didn’t say it on live television at 5 o’clock in the afternoon,” Ms Perino added.
“These are things that they’re quoting from other places. He didn’t say it on television,”
The co-host then added: “This is from the only person on The Five who ever swore," referring to Ms Perino, who said the word “a**hole” in a live recording of the weekly Fox News talk show in response to a video of an alligator in a convenience store.
In his latest round of tweets Mr Trump has demanded an apology from the Democratic congresswomen targeted by his racist comments.
He doubled down on his “go back home” remarks in front of reporters in the White House, adding: “If you’re not happy here, then you can leave”.