Trump insists border wall will be 'all concrete' — except where it’s 'see-through': ‘Makes sense to me!’

President Donald Trump insisted he had not backed off his campaign promise to build an impenetrable border wall, after a Republican ally described the proposal as metaphorical.

Sen. Linsey Graham (R-SC) told reporters Sunday after White House meeting that Trump's border security proposal might not include a physical wall, and outgoing chief of staff John Kelly said the "solid concrete wall" had been abandoned early in the administration.

“It’s just not about physical barriers. It’s about other things,” Graham said. “The wall has become a metaphor for border security, and what we’re talking about is a physical barrier where it makes sense.”

Trump, however, disagreed Monday morning in a tweet, saying he intended to build a concrete wall along the U.S.-Mexico border, except in areas where it would be made see-through at the request of authorities.

"An all concrete Wall was NEVER ABANDONED, as has been reported by the media," Trump tweeted. "Some areas will be all concrete but the experts at Border Patrol prefer a Wall that is see through (thereby making it possible to see what is happening on both sides). Makes sense to me!"