Trump: 'Solar wall' could 'pay for itself'

President Donald Trump said Wednesday his administration's proposed US-Mexico border could pay for itself -- if it was solar.

A "solar wall" could "create energy and pay for itself," the President said during a rally at the US Center in Cedar Rapids, Iowa.

"And this way, Mexico will have to pay much less money," Trump said. "And that's good, right? Is that good? You are the first group I've told that to. A solar wall. It makes sense. Let's see. We are working it out. Solar wall panels."

Trump, however, floated the idea of covering his border wall with solar panels earlier this month in a meeting with congressional leaders, according to sources familiar with the conversation.

"We have already started planning," Trump said in his first visit to Iowa since the election. "It will be built."

But Congress has yet to appropriate any money to the administration to follow through on Trump's border wall. After being rebuffed by Congress for money to build any wall in fiscal year 2017, the administration has asked appropriators for $1.6 billion to build 74 miles in 2018, according to the Department of Homeland Security.