A Republican candidate for governor in North Carolina has insisted he will not exit the race amid a report that he made controversial comments on a porn website more than a decade ago.

Mark Robinson characterised the CNN report, which alleged that he had referred to himself as a "black Nazi" on an adult forum, as "salacious tabloid lies".

He has been under pressure from state Republicans and members of Donald Trump's campaign team to quit the race, according to anonymous sources quoted by the Carolina Journal newspaper.

Kamala Harris, a Democrat, is hoping to wrest the potentially pivotal swing state from Trump, a Republican, in November's White House election.

Robinson, 56, is a former furniture manufacturer who was elected to be the state's first black lieutenant governor in 2020.

He won the gubernatorial nomination in March this year after receiving an endorsement from Trump, who called him "Martin Luther King on steroids".

According to the CNN report on Thursday, Robinson used to visit a porn website from 2008-12 called Nude Africa, with the username "minisoldr".

"I like watching tranny on girl porn... It takes the man out while leaving the man in!" minisoldr commented, according to CNN.

"And yeah I’m a 'perv' too!"

The BBC has not verified the CNN report.

In 2021, Robinson refused to apologise after he was criticised for saying that children in schools should not be learning about "transgenderism, homosexuality, any of that filth".

In a video posted to X, formerly Twitter, on Thursday, as the CNN story was being published, he denied wrongdoing.

"Let me reassure you, the things you will see in that story, those are not the words of Mark Robinson," he said.

"We are staying in this race. We are in it to win it."

He said he was the victim of a "high-tech lynching" by his white Democratic opponent, Josh Stein.

Opinion polls already suggest Stein, a Harvard-educated lawyer who is currently North Carolina's attorney general, has a firm lead in the race.

The deadline for withdrawing from the gubernatorial contest is Thursday evening as postal ballots go into the mail on Friday. Early voting in the state begins in less than a month.

Recent polling in North Carolina shows Harris and Trump effectively tied among likely voters.

The Tar Heel State has been a Republican stronghold, with only one Democratic presidential nominee winning there in the last 20-plus years.

Trump narrowly beat Joe Biden in North Carolina four years ago by less than 2%.

Democrats have campaigned heavily in the state this election season.