Washigton: President Donald Trump says he plans to call the heads of US Steel and other steel companies to come up with a new design for the barrier he's insisting must be built along the southern border.

That's despite the fact that his administration has already spent millions constructing wall prototypes near the border in San Diego.

Trump had once vowed to build a concrete border wall, but now says the barrier will be made of steel slats.

He tells reporters as he departs the White House for meetings at Camp David that he'll be asking the companies to design "a beautiful steel product" and "we'll use that as our barrier."

Trump's demand for billions for the barrier has forced a partial government shutdown that is now in its third week.


Earlier...

President Donald Trump stood firm on Sunday on his demand for billions of dollars to fund a border wall with Mexico, which has forced a shutdown of the US government now entering its third week.

"We have to build the wall," Trump told reporters as he left the White House for the Camp David presidential retreat, while conceding that the barrier could be "steel instead of concrete".

"It's about safety, it's about security for our country," he said. "We have no choice."

He also fired off a seeries of tweets.