That is specifically at the request of the president, who understands that in the hot temperatures down here, when something is painted black, it gets even warmer,' Noem said.

Noem announced Tuesday that the U.S.-Mexico border wall is being painted black in an attempt to make it more difficult for migrants to climb.

Homeland Security Secretary Kristi Noem says the entire southern border wall with Mexico is being painted black to deter illegal immigration, at President Trump's request.