A massive image of U.S. President Donald Trump as an alien intruder now towers above one of the busiest roads in Mexico City, urging motorists to "Make America Great Again."

The gaudy billboard sports a caricature of Trump with a blue-and-red fleshless face beneath his blond hair. It went up above the two-tier inner city ring road known as the Periferico a week ago after failing to find takers in the United States.

The 13-by-7-meter (43-by-23-foot) finger-pointing Trump, with a backdrop of an American flag, was originally intended to adorn a U.S. city, said its creator, Chicago-based artist Mitch O'Connell.