NFL players across the country protested during the national anthem ceremony Sunday in response to comments President Trump made calling for team owners to suspend or fire athletes who do not stand during "The Star-Spangled Banner."

Some football players in London linked arms and dropped to one knee and players back in the U.S. posted their support on Instagram and Twitter, some using the hastag #takeaknee.

The entire Pittsburgh Steelers team stayed in their locker room prior to their game agains the Chicago Bears as the "Star Spangled Banner" played, aside from one player, Alejandro Villanueva, an ex-Army Ranger who left the locker room to stand on the field.

"We're not participating in the anthem today," Steelers Coach Mike Tomlin told ABC News, adding the action is "not to be disrespectful to the anthem" but to remove the team "from this circumstance."

In a rally for Sen. Luther Strange, R-Ala., on Friday Trump said NFL owners should respond to players who protest by saying, "Get that son of a bitch off the field right now, he's fired. He's fired!"

He was alluding to Colin Kaepernick, a former San Francisco 49ers quarterback, who knelt last season during the national anthem to condemn racial injustice and police violence.

In a tweet Sunday Trump said NFL fans should stop going to football games until players who kneel during the national anthem are suspended or fired.