Washington, Jun 22 (IANS): US President Donald Trump has proposed to install solar panels on the wall he wants to be built along the border with Mexico, so that the energy produced will help finance it and that Mexico "will have to pay a lot less money".

"We're thinking of something that's unique, we're talking about the southern border, lots of sun, lots of heat. We're thinking about building the wall as a solar wall so it will generate energy and pay for itself," Trump said on Wednesday during a rally in the city of Cedar Rapids, Iowa.

"And this way, Mexico will have to pay much less money. And that's good, Right?"

The idea of putting solar panels on the wall had already been circulating for two weeks in Washington D.C. since the President spoke of the plan at a private meeting with a group of Republican lawmakers on June 6, but Trump had not mentioned it in public until now, reports Efe news.

He suggested the plan was his own, saying: "Pretty good imagination, right? Good? My idea", reports the BBC.

During his campaign, Trump pledged to build a wall along the Mexican border to stop illegal immigration and drug trafficking.

Trump insisted he would make Mexico pay for the bill, but President Enrique Pena Nieto has dismissed the idea.

More than 200 companies have reportedly responded to an invitation from the Department of Homeland Security (DHS) to submit designs for the wall.

Among them was one from Gleason Partners in Las Vegas that proposed a wall of steel, cement and solar panels.