US Senator Ted Cruz has accused the head of America's broadcast regulator of acting like a mafioso in the suspension of late-night host Jimmy Kimmel - the sharpest attack yet from a conservative Republican on the controversy.

He said Federal Communications Commission (FCC) chairman Brendan Carr's threat to ABC over their comedian's monologue about slain conservative influencer Charlie Kirk was dangerous as hell.

That's right out of Goodfellas, the Texas Republican said, as he affected a mobster's accent.

Other Republicans in Congress have been more muted in their criticism of how the FCC pressed Disney-owned ABC to take action on Kimmel, who was indefinitely suspended on Wednesday.

The row started after Kimmel said in his monologue on Monday that the Maga gang were desperately trying to characterise this kid who murdered Charlie Kirk as anything other than one of them and trying to score political points from it.

He also likened Trump's reaction to the conservative political activist's death to how a four-year-old mourns a goldfish.

Brendan Carr called those comments sick and threatened to take action because the host had appeared to directly mislead the American public.

Conservative critics say Kimmel was pushing a false narrative by suggesting the suspect in the Kirk killing was a Make America Great Again Republican. While the exact motive is still not known, on Sunday - before Kimmel spoke - the Utah governor had said the suspect was indoctrinated by leftist ideology.

On his podcast Verdict with Ted Cruz, the senator emphasised on Friday that he hated what Kimmel said about Kirk, and he is thrilled that he was fired. He also said Carr was a good guy. However, Cruz cautioned, What he [Carr] said there is dangerous as hell... He threatens, explicitly, we're going to cancel ABC's licence. That's right out of Goodfellas.

In the Oval Office on Friday, President Donald Trump defended Carr and said I disagree with Ted Cruz, who is ordinarily one of his staunchest allies. Another Republican Senator, Thom Tillis of North Carolina, told reporters that Cruz was absolutely right in his criticism of Carr.

The FCC is in charge of granting broadcast licences to networks such as ABC, NBC, and CBS, and they are required under statute to be in the public interest. The broader implications of the FCC's actions and the response from Cruz highlight the delicate balance between free speech and media regulation in today's political environment.