Scott Olson / Getty Images

Donald Trump told supporters Wednesday that the controversial planned wall dividing the US and Mexico could be built using solar panels.

"We're thinking about building the wall as a solar wall, so it creates energy and pays for itself. And this way, Mexico will have to pay much less money, and that's good, right?" Trump said at an Iowa rally, according to the BBC.

More than 200 companies have submitted plans for the wall to the US Department of Homeland Security, some of which already incorporate solar technology in their designs.

Trump has said that a border wall would curb immigration between Mexico and the US and has argued that Mexico itself would foot the bill -- a notion that Mexican president Enrique Peña Nieto has not supported.

The president on Wednesday also said he would soon introduce legislation to restrict immigrants from accessing welfare during their first five years in the US, CBS News reported.