Homeland Security Secretary Kristi Noem announced that the entire U.S.-Mexico border wall will be painted black, at President Trump’s request, to make it hotter and harder to climb, while also helping prevent rust.

During a visit to New Mexico, she highlighted the wall’s height and depth as deterrents and said about half a mile of barrier is being built daily.

The effort is part of a broader Trump-backed push, including military deployment and land control measures, funded by roughly $46 billion in new congressional appropriations, CBS News has reported.

The announcement comes amid a historic drop in illegal border crossings, with just over 6,000 apprehensions in June.