A video shows U.S. President Joe Biden wearing a hat bearing the slogan of his predecessor and Republican presidential candidate, Donald Trump. So, what’s the story behind it?

• Biden and Harris launched an aggressive attack on Donald Trump

• Trump tries to attack Harris through her father… What happened?

Biden wore the hat during an event commemorating the 23rd anniversary of the September 11, 2001, attacks.

The footage was captured inside a fire station in Shanksville, Pennsylvania, the location where United Flight 93 crashed on September 11, 2001.

• Trump and Harris: The Real Showdown Begins on Tuesday

• Indian or Black?.. Trump Plays on Harris’s Origins and the White House Responds

While touring the fire station, Biden happened to meet a Trump supporter, who offered him a hat. In return, he gave Biden a hat featuring Trump’s campaign logo, saying, “In this spirit, the president should wear a Trump hat.” Biden briefly placed the hat on his head.

• Trump or Harris? The Stock Market Predicts the Winner

• FBI Settles the Debate: Was It a Bullet or Shrapnel That Injured Trump’s Ear?

Andrew Bates, the White House spokesperson, confirmed that Biden‘s gesture was intended to “show the unity of the country.”