US President Donald Trump on Friday threatened to shut down America's southern border with Mexico next week unless Mexican authorities immediately halt all illegal immigration. Trump emphasized "I am not kidding around" about closing the border, even though such a severe move could hit the economies of both countries.

"If Mexico doesn't immediately stop ALL illegal immigration coming into the United States through our southern border, I will be closing the border, or large sections of the border, next week," The President said on Twitter.

Trump, who also cut US aid to three Central American nations whose citizens are fleeing north, claimed closing off border crossings, key avenues for trade with Mexico, "would be a good thing!"

"It could mean all trade" with Mexico, Trump said when questioned by reporters in Florida. "We will close it for a long time." Though Trump has previously threatened to close the border and has not followed through, his administration moved to cut direct aid to El Salvador, Guatemala, and Honduras. The State Department said in a statement that it will suspend 2017 and 2018 payments to the trio of nations that have been home to some of the migrant caravans that have marched through Mexico to the U.S. border.