A man snatched an American flag off a vehicle in Manhattan festooned with support slogans for President Trump — and was promptly arrested for the theft Sunday, police said.

Jared Handler, 37, grabbed the flag off of Rob Cortis’s vehicle as he was driving near 14th Street and Eighth Avenue at about 6:40 p.m., police said.

Handler then ran toward Union Square with the flag, but was busted by cops not far from the intersection, authorities said.

As the theft unfolded, passersby noticed Cortis’s pro-Trump vehicle and started chanting anti-Trump statements, police sources said.

A few of the pedestrians yelled at Cortis, he told The Post.

“A couple people flipped me off,” Cortis said in a phone call on Sunday. “A couple yelled out ‘F-Trump’ and flipped me off.”

Cortis tours the country in a vehicle he dubbed the “Trump Unity Bridge,” a handmade float emblazoned with pro-Trump slogans and decorations. He’s currently on a “Building the Wall Tour,” according to his website.

“We are stopping in both large cities and small towns across the country delivering a message of Unity while discussing the importance of securing America’s southern border,” Cortis wrote about the tour.

Cortis slammed Handler after the theft, and said he would help police to prosecute him.

“He’s stealing a flag and destroying it,” Cortis told The Post.

“Why would he want to be in our country if he’s stealing a flag and destroying it?” he added.

Handler, of Manhattan, was hit with petit larceny, disorderly conduct, criminal mischief and criminal possession of stolen property for his stunt.

He was also given a violation for carrying a small amount of marijuana, police said.

He could not immediately be reached for comment.