Donald Trump has decided to slap tariffs on goods from Mexico because the Mexican government, he says, isn’t doing enough to stop migrants from Central America coming to the United States. And he wants it to begin soon.

NBC writes:

In a statement, the White House said the new tariffs would go into effect on June 10 and would rise by 5 percentage points every month — to 10 percent on July 1, 15 percent on Aug. 1 and so on — until they hit 25 percent on Oct. 1.

“Tariffs will permanently remain at the 25 percent level unless and until Mexico substantially stops the illegal inflow of aliens coming through its territory,” it said.

If you are wondering how this will force the Mexican government to stop migrants, you aren’t alone.

The Washington Post adds:

Mexico exported $346.5 billion in goods to the United States last year, from vehicles to fruits and vegetables. And many manufactured goods cross the border several times before they are sold to U.S. consumers.

The economic consequences of Trump’s new plan could be swift and severe. U.S. companies will be required to pay the tariffs in the form of import penalties, and they often pass those costs along to consumers.