WASHINGTON (Reuters) - U.S. President Donald Trump on Wednesday criticized Nike Inc for its new advertising campaign featuring Colin Kaepernick, the NFL quarterback who sparked controversy by kneeling in protest during the national anthem.

Trump, without offering evidence, said in a post on Twitter that the sportswear company was “getting absolutely killed with anger and boycotts.” He also continued to blast National Football League players for their protests over racial and social injustice.

Representatives for Nike could not be immediately reached for comment on Trump’s tweet. Shares of the company were up less than one percent in midmorning trade on Wednesday; the stock had dropped nearly 4 percent at one point on Tuesday.

The footwear and apparel maker’s campaign this week further stoked a national debate over social justice that Kaepernick and other NFL players sparked with their protests aimed at addressing police brutality against minorities, racial injustice, and reforming the criminal justice system.

Trump has embraced the issue as a political cause, frequently criticizing players for taking a knee at games and questioning their patriotism. Critics have defended their protests as a fundamental American right to free speech.

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On Tuesday, he criticized Nike’s decision but also appeared to defend the right for such movements.

Marketing experts predicted that the brand recognition sparked by the ads would be successful in the long run, despite current calls for boycotts on social media.

NFL players and the league are continuing to negotiate over the issue of protests.

(The story was refiled to add dropped words in the lead paragraph)