The black paint will also prevent rust on the steel, said US Border Patrol Chief Michael Banks.

Homeland Security Secretary Kristi Noem said the entire southern border wall will be painted black, so it will get hot in the sun and "make it even harder for people to climb."

Homeland Security Secretary Kristi Noem said Tuesday that the entire border wall along the southern border with Mexico is going to be painted black to make it hotter and deter illegal immigration — a...