Donald Trump has responded publicly to Nike’s decision to make Colin Kaepernick the face of its new advertising campaign.

It is two years since Kaepernick knelt during the national anthem to highlight social and racial injustice in the United States. The NFL quarterback’s movement spread around the NFL, causing Trump to say last year that any player who knelt during the anthem was a “son of a bitch” and should be fired.

While many have lauded Kaepernick’s stance, others have attacked him for what they see as disrespect to the flag and the military.

“I think it’s a terrible message that [Nike] are sending and the purpose of them doing it, maybe there’s a reason for them doing it,” Trump told the Daily Caller on Tuesday. “But I think as far as sending a message, I think it’s a terrible message and a message that shouldn’t be sent. There’s no reason for it.”

The president did, however, acknowledge that Kaepernick and Nike had a right to express themselves. “In another way, it is what this country is all about, that you have certain freedoms to do things that other people think you shouldn’t do, but I personally am on a different side of it,” Trump said. He also mentioned that Nike pay him “a lot of rent” as its flagship New York store is in a building owned by Trump. The company last year announced it would leave the property.

Kaepernick, who led the San Francisco 49ers to the Super Bowl in 2013, left San Francisco at the end of the 2016 season and has not been picked up by a team since. The fact that teams with a need for a quarterback have passed up the chance to sign Kaepernick left many to believe owners were either punishing him for his stance or believe his presence would alienate fans. Kaepernick and his former teammate Eric Reid, who was also one of the first players to kneel during the anthem, have filed grievances claiming owners have colluded to keep them out of the league.

Nike has a history of campaigns that touch on race in the United States. When Tiger Woods turned professional, the company launched the Hello World campaign, in which the athlete discussed the history of racial discrimination in golf. That campaign led to boycotts and the Kaepernick ad has been similarly divisive. On Tuesday, dozens of videos were posted to social media of Nike products being burned by angry customers.

The NFL and players union have yet to announce an anthem policy after the league initially ruled that teams could be fined if players knelt during the Star-Spangled Banner. On Tuesday, the NFL issued a statement saying it supported social-justice initiatives.

“The National Football League believes in dialogue, understanding and unity,” said an NFL spokesperson in a statement. “We embrace the role and responsibility of everyone involved with this game to promote meaningful, positive change in our communities. The social justice issues that Colin and other professional athletes have raised deserve our attention and action.”