LeBron James mocked Donald Trump after the president labeled him a 'total disgrace' for practicing his golf swing during the national anthem ahead of a clash against the New York Knicks earlier this week.

Now viral footage of the Philadelphia 76ers star shows James pretending to swing a golf club and practicing his free throw technique while The Star-Spangled Banner was sung at Madison Square Garden.

Trump, a longtime critic of James, lashed out at the NBA legend in an explosive Truth Social post on Thursday. 

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Trump wrote: 'While listening to our National Anthem, LeBron James disrespects our Country! I said right from the beginning that he’s no good, a TOTAL DISGRACE. 

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

James, 41, was asked about the president's comments following the 76ers' stunning comeback win over the Cleveland Cavaliers. 

He said: 'It must be a slow news day at the office, you know.'

Trump doubled down on his criticism of the NBA superstar during a rally in Iowa on Thursday night. 

He said: 'During the national anthem, he's practicing his golf swing... what the hell is that? It's a big scandal... what it's all about? I don't understand it.'

The comments mark the latest chapter in a long-standing feud between the four-time NBA champion and the president, which dates back to James labeling him a 'bum' in 2017. 

Earlier this year, Trump launched an astonishing attack on James just hours after the 41-year-old revealed he'd be signing with the 76ers.

Just hours after LeBron's 24th season in the NBA was confirmed, Trump was asked to weigh in on who holds the title of the greatest basketball player of all time.

Trump said: 'Michael Jordan's a guy that's a friend of mine, I've played golf with him.

'He's a really good guy and I think LeBron is - maybe he's a racist, but maybe he doesn't like Trump, I don't know - but I only like people that like me, so I would say Michael Jordan all the way.'

James, 41, has frequently used his platform to criticize Trump, previously endorsing Democratic candidates and launching voting-rights initiatives across the country.

Their bad blood first spilled into the public eye during Trump's first presidency after he withdrew a White House invitation extended to Golden State Warriors star Steph Curry over his hesitation to visit.

Outraged by the gesture, James immediately jumped to his rival's defense, tweeting at Trump: 'U bum, Steph Curry already said he ain't going! So, therefore ain't no invite. Going to White House was a great honor until you showed up!'

The public spat escalated in 2018 when Trump announced he was pre-emptively banning both the Cleveland Cavaliers and Golden State Warriors from visiting the nation's capital following that year's NBA Finals.

Refusing to be fazed, James swiftly shut down the snub, declaring at the time: 'Winning a championship is way bigger than getting invited to the White House, especially with him in it.'