Donald Trump on Saturday night stoked the controversy over his call for punitive action against NFL players who take a knee or otherwise protest during the national anthem, tweeting anew that they should remain standing out of respect for the nation and its flag.

The president took time from a Twitter rant against criticism of the federal response to hurricane damage in Puerto Rico to tweet: "Very important that NFL players STAND tomorrow, and always, for the playing of our National Anthem. Respect our Flag and our Country!"