Biden jokingly puts on Trump hat at event in Shanksville, PA: Watch

On Wednesday, after a morning of commemorations marking the 23rd anniversary of the Sept. 11 attacks, President Joe Biden briefly donned a red Trump hat at an event in Pennsylvania.

The now-viral moment shows Biden jokingly putting on the hat during a visit with firefighters in Shanksville, Pennsylvania, near the site where one of the four hijacked planes crashed on Sept. 11, 2001. Trump also appeared in Shanksville later Wednesday.

After the footage went viral on the internet, the White House said Biden wore the hat as a sign of unity.

A video of the event shows Biden exchanging a few friendly words with a Trump supporter in the crowd before the two men swap hats – a gesture that White House deputy press secretary Andrew Bates called a sign of “bipartisan unity.”

Watch the viral moment: