United States president Donald Trump posted a tweet on Monday calling for an apology from NASCAR driver Bubba Wallace.

Trump, who also criticized the sport for banning the Confederate flag from its races and events, implied that NASCAR's only full-time black driver was party to a "hoax" after an incident where a rope that was tied like a noose was discovered by one of his crew members in his garage at Talladega Superspeedway on June 21.

The following day in a demonstration of solidarity, all NASCAR drivers and crew members walked behind Wallace's number 43 car to the front of the field prior to the makeup race, and then one by one comforted an emotional Wallace and hugged him. 

Trump's Tweet read: ''Has @BubbaWallace apologized to all of those great NASCAR drivers & officials who came to his aid, stood by his side, & were willing to sacrifice everything for him, only to find out that the whole thing was just another HOAX?''

"That & Flag decision has caused lowest ratings EVER!'' 

Contrary to Trump's claims of a low television audiences, Fox reported ratings for last month's Cup Series race at Martinsville were up 104 per cent on the same spot in the calendar from last year.

Chevrolet driver Tyler Reddick responded to Trump in support of Wallace.

"We don't need an apology," he tweeted. "We did what was right and we will do just fine without your support."

A few days after the rope was discovered, the FBI said it had been positioned in the stall at Talladega since as early as last year and was a garage-door pull rope that had been fashioned like a noose. The FBI also determined earlier in the week that Wallace was not the target of a hate crime.  

Wallace has spoken out about racial injustice and racism, and helped push NASCAR to ban the Confederate flags from its races, events and properties on June 10. 

"I was relieved just like many others to know that it wasn’t targeted towards me,” Wallace, who neither found nor reported the noose, told NBC’s Today in the aftermath of the incident and the FBI's investigation.

"But it’s still frustrating to know that people are always going to test you and always just going to try and debunk you and that’s what I’m trying to wrap my head around now, from people saying I’m a fake … or that I reported it when it was information that was brought to me.”

Following George Floyd's death while in the custody of Minneapolis police on May 25, protesters have pushed for the removal of statues and monuments of known racists, as well as the Confederate flag. 

Trump, however, criticized these protesters during his speech at Mount Rushmore over Independence Day weekend, saying: "Our nation is witnessing a merciless campaign to wipe out our history, defame our heroes, erase our values, and indoctrinate our children."