British commentator Piers Morgan called Monday for President Trump to apologize and change his mind about NFL players who kneel during the national anthem as a form of protest.

Morgan wrote in a Daily Mail column that, while he had initially also opposed now-NFL free agent Colin Kaepernick's protest against racial injustice during the national anthem, he had eventually changed his mind.

He wrote that he began to view Kaepernick more favorably after he switched from sitting during the national anthem to kneeling a few games into the start of his protest.

"These black football players are kneeling specifically to protest against racial inequality. An inequality that demonstrably exists," Morgan wrote. "It's time to start healing wounds, not inflict further damage."

Morgan said Trump should invite Kaepernick to the White House "and hear him out," adding that he "owes all those players, and their mothers, a heartfelt apology."

"Let this brave, bold young man tell you face to face what he feels is inherently wrong with the way black Americans are still being treated," he wrote.

"Then pose for a photo as you shake Kaepernick's hand in the Oval Office and tell black Americans to a TV camera that you hear them, you will listen to them, and you will strive to make their lives better."

Morgan's column comes after a weekend of protests by NFL players during the national anthem, after Trump attacked players who kneel during the anthem at a Friday rally.

"When people like yourselves turn on television and you see those people taking the knee when they are playing our great national anthem - the only thing you could do better is if you see it, even if it's one player, leave the stadium," Trump said at a campaign rally Friday. "I guarantee things will stop."

He also said that NFL owners should fire players that kneel during the anthem.

Football players across the league responded by protesting during the anthem on Sunday by kneeling, sitting or locking arms in solidarity. Three teams chose to stay in their locker rooms during the anthem.