As many posters have already pointed out, this means Americans will pay for the wall.

And all because of Trump's fragile pre-adolescent ego.

During the primary, Trump proposed a plan to build a wall to keep out illegal Mexican border crossings.  Trump being Trump, he had to go further and claim he would make Mexico pay for it.  A ridiculous claim, by any sane assessment.

And it was ridiculed - by opponents and the media - and him for making it. Trump's ego being what it is, there was probably never a chance he would back down.

Ego-soothing is - obviously - not a rational criteria for public policy, but it seems it will be a constant for the duration of the Trump presidency.