WASHINGTON - US President Donald Trump denied stoking racial tensions Monday, insisting his charged comments that prompted a wave of symbolic protests by NFL players were about patriotism, not race.
After a volley of verbal attacks on black athletes led players across the country to kneel during the US national anthem in protest this weekend, the besieged president played defence on Twitter.
Trump had kicked off the furore by attacking players like Colin Kaepernick -- who first took a knee through renditions of the "Star-Spangled Banner" during last year's American football season -- as a "son of a bitch" who should be fired.
In a separate feud, Trump also disinvited basketball superstar Stephen Curry from a White House event.
More than pro 150 players from across the country's most popular sport took a defiant stance, kneeling, linking arms or raising clenched fists during the anthem before 14 games.
The US leader doubled down on those remarks by urging fans to boycott the NFL as long as the protests continued.
And keeping the issue alive for a fourth day, Trump on Monday insisted, "The issue of kneeling has nothing to do with race. It is about respect for our Country, Flag and National Anthem. NFL must respect this!"
Trump -- who faces low poll numbers and is struggling to enact his agenda -- on Monday tried to single out the NFL players who protested.
"Many people booed the players who kneeled yesterday (which was a small percentage of total). These are fans who demand respect for our Flag!" he tweeted.
He also pointed to the Pittsburgh Penguins acceptance of a White House invitation and support from racecar fans.
"So proud of NASCAR and its supporters and fans. They won't put up with disrespecting our Country or our Flag - they said it loud and clear!" Trump tweeted.
But driver Dale Earnhardt also took to Twitter, implicitly rebuking Trump with a quote former president John F Kennedy: "All Americans R granted rights 2 peaceful protests Those who make peaceful revolution impossible will make violent revolution inevitable."
Trump also drew a furious backlash from NBA stars, including superstar LeBron James, who described the president as a "bum."
"He doesn't understand how many kids, no matter the race, look up to the President of the United States for guidance, for leadership, for words of encouragement," said James.
"The people run this country. Not one individual. And damn sure not him."
Trump has whole-heartily embraced the controversy, with his advisors believing it plays well with his largely white base.
Trump also changed his Twitter background photo to an American flag and stated that the "White House never looked more beautiful than it did returning last night."
Critics accuse Trump of creating a diversion.
His efforts to repeal Barack Obama's healthcare reforms have run aground and would-be signature tax reforms are giving way to much less ambitious tax cuts.
At the same time Trump faces a number of challenges from overseas, not least a war of words with North Korea that threatens to become a shooting war.
North Korea in recent weeks detonated its sixth nuclear bomb and has test-fired intercontinental missiles -- saying it needs to defend itself against hostility from the United States and its allies.
Addressing the UN General Assembly last week, Trump responded by calling leader Kim Jong-Un a "Rocket Man" on a "suicide mission," prompting Kim to warn in turn that the US president would "pay dearly" for his threat.
Escalating tensions further, North Korea's foreign minister said Monday that Trump had "declared a war" on North Korea, while conveying a threat to shoot down US bombers.