INDIANAPOLIS (AP) — Vice President Mike Pence left the 49ers-Colts game after about a dozen San Francisco players took a knee during the national anthem Sunday, the latest move by President Donald Trump's administration to clash with NFL players over patriotism and public demonstrations.

The former Indiana governor flew in so he could watch Peyton Manning's jersey retirement ceremony. Pence didn't stick around long.

Right around kickoff, Pence wrote on Twitter: "I left today's Colts game because @POTUS and I will not dignify any event that disrespects our soldiers, our Flag, or our National Anthem."

The White House also issued a statement from Pence, in which he said Americans should rally around the flag. Pence said: "I don't think it's too much to ask NFL players to respect the Flag and our National Anthem."

After Pence's walkout, Trump tweeted: "I asked @VP Pence to leave stadium if any players kneeled, disrespecting our country. I am proud of him and @SecondLady Karen." The tweet raised the question of whether Pence's actions had been planned in advance.

San Francisco 49ers safety Eric Reid said Pence's departure looked like "a PR stunt."

"He knew our team has had the most players protest, he knew that we were probably going to do it again," Reid said. "This is what systemic oppression looks like: man with power comes to the game, tweets a couple things out and leaves the game in an attempt to thwart our efforts."

Trump has called on NFL owners to fire players who don't stand for the anthem and urged fans to boycott games in a series of tweets after he first criticized the demonstrations during a Sept. 22 rally in Alabama. White House officials have viewed it as a winning issue for the president, who has sought to remain closely connected to his working-class base of Midwestern voters who helped elect him in 2016.

NFL spokesman Brian McCarthy declined to comment on Pence's walkout. The Colts also had no comment, and after their 26-23 overtime victory, Indianapolis coach Chuck Pagano steered clear of the issue.

"No," Pagano said when asked if he had any reaction to what Pence did.

Colts players stood in unison, locking arms but standing throughout the anthem.

But the 49ers have been among the most visible protesters in the league. Last year, former quarterback Colin Kaepernick started the movement to kneel or sit during the anthem, and Reid and other teammates backed him up on and off the field.

Pence flew in on Saturday after a statue of Manning was unveiled, an event attended by a number of luminaries including NFL Commissioner Roger Goodell. The vice president had spent most of Saturday honoring victims of the Las Vegas shooting before returning to his home state.

Aides to the vice president did not respond to questions on whether he had planned to make the public walk-out in the game against the 49ers, who have regularly held the demonstrations. Pence's trip to Las Vegas and Indianapolis was announced on Friday.

After leaving the game, Pence departed Indianapolis for a three-day trip to California that includes three fundraisers and an event on the president's push for a tax overhaul.

Pence, who attended last year's Super Bowl, is a noted sports fan and it was the second major event he's attended in his home state since taking office in January. He also attended May's Indianapolis 500, a family tradition.

------

Associated Press writer Ken Thomas in Washington contributed to this report.