US President Donald Trump has given Mexico "one-year warning" to do more to end the flow of drugs and people into the United States.
It follows his threat to close the border between Mexico and the US.
This is adding to the uncertainty felt by businesses that depend on cross-border trade.
Mexico is the US's third-largest trading partner. A few days of border closure would mean significant losses to the US car industry and rising prices in American grocery stores.
Al Jazeera’s Heidi Zhou-Castro reports.