The President of the United States on Monday canceled a reception for the 2018 National Football League (NFL) champion Philadelphia Eagles to the White House, scheduled for Tuesday, due to the players' protests during the singing of the national anthem.

Donald Trump withdrew the invitation he had extended to the Philadelphia Eagles to the White House after finding that they intended to visit in a "small delegation," and not with their entire staff as is customary at such receptions.

"They disagree with their president because he insists that they proudly stand for the national anthem, hand on heart," a spokesperson for the White House said in a statement.

Instead of hosting a reception for the Eagles, Trump plans to receive a group of Eagles fans, who intended to accompany the team to the White House.

Trump has been in confrontation with NFL players for months after they kneeled down or stood idly during the singing of the national anthem before the games to protest racial injustice and police brutality against African-Americans in the U.S.

These protests began at the end of last season.

The NFL owners approved a new policy in May to impose fines on teams whose players kneel during the national anthem, although they do allow the players to remain in the locker room until the game starts.

Trump lauded the NFL's policy, saying of players who do not stand up during the anthem "maybe you shouldn't be in the country."

The NFL is the most popular league in the U.S. and American football is the most money moving sport, with a turnover of $14 billion in 2017.

The Philadelphia Eagles won their first Super Bowl in 2018 after beating the 10-time NFL champion New England Patriots 41-33.