OAKLAND, Calif. (KTVU) - President Trump repeatedly threatened Friday that he would close the southern border or large sections of the border with Mexico next week if Mexico "doesn’t immediately stop ALL illegal immigration coming into the United States through our Southern Border" he wrote in a tweet.
The President said he doesn't see any financial loss for the United States.
"We'll keep it closed for a long time - I'm not playing games," the President said Friday.
In a news conference he also said, "With a deficit like we have with Mexico and have had for many years, closing the border will be a profit-making operation."
President Trump's threat drew sharp criticism.
The U.S. Chamber of Commerce said it would be quote "an unmitigated economic debacle" that could threaten 5 million American jobs.
The Chamber says the U.S. and Mexico trade about $1.7 billion in goods every day.
California Senator Dianne Feinstein said in a statement it would be an "economic disaster."
"It would be extremely harmful economically," said Sean Randolph, Senior Director of the Bay Area Council Economic Institute.
"Mexico is our biggest export market from California," said Randolph, "About 15.5%-16% of all our exports to the entire world go to Mexico."
Randolph says Bay Area technology companies such as Google's parent company Alphabet, Oracle, Cisco, and HP have partnerships and interests in Mexico, including the production of components.
"A lot of our companies have major operations in Mexico."
Randolph says many companies no longer keep large warehouses of extra parts in stock so a border shutdown could have severe impacts.
"I think the big one is the supply chains. These are binational supply chains that are really important to our companies and if you disrupt them, you're disrupting their businesses and the employment and other activity that we have here," said Randolph.
Smaller businesses such as neighborhood produce markets could also see an impact on items for their customers.
"Long term definitely would have an impact on us," said John Lundholm, a Village Market employee who has served as a produce buyer.
At Village Market, avocados, tomatoes, tropical fruits, and winter vegetables are often available from Mexico when they're out of season in California.
"We probably get about 40% of our produce from south of the border so especially this time of year."
The White House did not respond to questions about whether any border closure would include air travel.
Mexico's foreign relations secretary, responded with a tweet saying Mexico "doesn't act based on threats" and is "the best neighbor" the U.S. could have.