In short: 

US President Donald Trump has branded LeBron James a "total disgrace" over a perceived lack of respect for the national anthem.

Trump was angered after footage from the Philadelphia 76ers' season opener showed James practising his golf swing during the anthem.

What's next? 

James and the 76ers are taking on the Cleveland Cavaliers in their home opener in Philadelphia on Friday morning AEDT.

US President Donald Trump has accused LeBron James of disrespecting the United States after the NBA star appeared to continue his warm-ups while the national anthem was performed before Philadelphia's season opener on Wednesday AEDT.

"I said right from the beginning that he's no good, a TOTAL DISGRACE," Trump said of James in a social media post sharing the video.  

"LeBron James should apologise to all of those Great American Warriors and Heroes who died for the American Flag, and all that our Country stands for!"

James appeared to practice a golf swing and jump shot as The Star-Spangled Banner was performed at New York's Madison Square Garden. 

James, starting his first season with Philadelphia, was lined up alongside teammates who mostly stood still during the anthem.

Trump and James have been critical of each other for years, occasionally trading public swipes.

James offered a short response to Trump's comments when questioned, declaring it was a "slow news day in the office".

Coach Nick Nurse had talked at length since training camp opened about the Sixers' need to tune out outside distractions. Hours before their home opener, the Sixers had to deal with one from the president.

"I think that goes right in with other outside noise we've already had," Nurse said before Friday's game against the Cleveland Cavaliers. 

"I keep saying the same thing. All I really care about is getting to the practice floor, getting them in the film room, getting them to the game floor. The focus that they've had and the intent and all the stuff like that has been outstanding."

AP