The U.S. owes Mexico $163 million a year, according to the World Trade Organization.
That's because the U.S. had been penalizing Mexico over tuna — claiming the product from Mexico wasn't "dolphin safe," which means no dolphins were killed by the fishermen.
Mexico challenged that with the WTO, claiming its fishermen followed all international rules and regulations.
The WTO agreed and ruled that Mexico could place trade sanctions on the U.S. of up to $163 million a year, enough to make up Mexico's estimated loss.
The additional tariffs won't add much to the nearly $50 billion trade deficit the U.S. already holds with Mexico. But the ruling is a political black eye for President Trump, who still insists Mexico will pay for a border wall between it and the U.S.
And the WTO order is another wrinkle in Trump's plans to get a better trade deal with Mexico by renegotiating the North American Free Trade Agreement, or NAFTA.