Using black paint to make the entire US-Mexico border wall hotter and harder to climb was reportedly Trump's idea.

The wall along the southern border will be painted black in an effort to make the structure too hot to climb, Department of Homeland Security Secretary Kristi Noem announced Tuesday, saying the suggestion came from President Donald Trump.

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.