AVA- Trump on Friday warned that the border closure could happen as early as next week.
"There's a very good likelihood that I'll be closing the border next week, and that will be just fine with me," Trump told reporters at his Mar-a-Lago resort.
He said he will "keep the border closed" unless the Mexican government acts.
“If they don't stop it we will keep the border closed. And we will keep it stopped for a long time," Trump said. "I’m not playing games.”
He added that Mexico must take action against two incoming migrant caravans and work to stop others from reaching the border.
“They have to grab it and they have to stop it. We right now have two big caravans coming up from Guatemala, massive caravans, walking right through Mexico. Mexico is tough. They can stop them. But they chose not to," he said. "If they don’t stop them, we’re closing the border."
Trump’s warning came more than a month after the end of a partial government shutdown triggered by a fight in Congress over Trump's demands for funding for a wall at the Mexico border.
In a series of tweets on Friday, the US president accused Mexico of making "a fortune" from America that is greater than its costs of protecting the border.
Trump blamed Democrats for the problems, and said they were responsible for giving Washington weak immigration laws.
Trump is also trying to convince the Congress to sign off on a revised trade agreement with Mexico and Canada that his administration negotiated last year.
The US Census Bureau says a border shutdown would disrupt tourism and commerce between the two countries, which totaled 612 billion dollars last year.
Mexican Foreign Minister Marcelo Ebrard has reacted to Trump’s remarks, saying his country does not act on the basis of threats.
"Mexico does not act on the basis of threats. We are a great neighbor," Mexican Foreign Minister Marcelo Ebrard said on Twitter.
"(Ask) the million and a half Americans who chose our country as their home, the largest community of (Americans) outside the U.S. For them we are also the best neighbor they could have," he added.