Trump's Mexico border wall?

Trump is standing firm on his promise to build a US-Mexico border wall.

David Muir: When does construction begin?

President Trump: As soon as we can. As soon as we can physically do it, we're ...

Muir: Within months?

Trump: ... I would say in months, yeah. I would say in months. Certainly, planning is starting immediately.

Mexican architecture firm Estudio 3.14 drafted a plan to showcase how impractical the wall is. The so-called "Prison-Wall" stretches 1,954 miles. It stretches through mountain ranges, presenting major construction challenges. The firm estimates the wall could take 16 years to build and cost $25 billion. Maintenance and border patrol could cost an additional $2.1 billion a year. The plan includes a prison capable of holding 11 million deported, illegal immigrants. The rendering also features a shopping mall for Americans to enjoy.