US President Donald Trump says he ‘may have to close up’ the United States

People walk past AFP pictures on the life in the US-Mexico border, during the opening of an exhibition in the bordering city of Ciudad Juarez, Mexico, on May 4, 2018. (Photos by AFP)

US President Donald Trump is upping the ante for undocumented immigrants, threatening to “close up” the southern border to halt the influx of immigrants.

"We may have to close up our country to get this straight," he said at a business roundtable in Cleveland, Ohio, on Saturday.

He asserted that his administration is working to ameliorate the nation's border controls, adding that "much more money" is needed for that purpose.

"You can't allow people to pour into our country like they're doing," said the president. "If we don't have borders, you don't have a country."

Trump further criticized what he called "open border" policies, promoted by the Democrats.

There has allegedly been a surge in the number of immigrants entering the country from the US southern border with Mexico, according to US Customs and Border Protection.

The Republican president has vowed to crack down on immigration but has failed to get his complete agenda through so far.

Children from the Anapra area observe a binational prayer performed by a group of religious presbyters on the border wall between Ciudad Juarez, Chihuahua state, Mexico and Sunland Park, New Mexico, US, on May 3, 2018.

In spite of his self-proclaimed deal making abilities, Trump has come up short within his own party to raise money for the wall he had promised to build on the border with Mexico during his 2016 campaign

Earlier this year, the Republican–controlled Congress allocated billions less than the White House demanded, only $1.6 billion, for border security in a trillion-dollar spending bill.

Since campaigning for the 2016 presidential election, Trump has been accused of stoking racial, ethnic and religious tensions lurking within America.