Security was tight on the Mexico-U.S. Border in the city of Tijuana ahead of a visit by U.S. President Donald Trump to visit border wall prototypes.

Mexican federal police and troops patrolled the Mexican side of the border as residents of a poor Tijuana slum called the project a waste of money and laughed at the idea the monolithic slabs will stop desperate immigrants.

Several locals called Trump”Loco” for thinking that spending billions of dollars on barriers would stop people determined to escape poverty and violence in Mexico and Central America

The prototypes, designed by six U.S.-based companies and unveiled last October, stand a few feet apart on the eastern edge of San Diego, several hundred feet from the rusty, stunted existing fence.

Trump has sought 18 billion dollars in funding to build the wall over the next two years.