President Donald Trump threatened Thursday to double U.S. tariffs on Mexican goods unless Mexico stops a migrant caravan traveling north. In a Truth Social post, he said tariffs would rise immediately if Mexico failed to act. He gave no list of goods, tariff rates or start date. The White House’s published actions page showed no implementing order Thursday morning.

Reuters reported that about 1,500 people, most from Central America, set out Tuesday from Tapachula, a city in southern Mexico near Guatemala. Trump said the migrants would be barred from entering the United States and said he had informed Mexican officials and U.S. border agencies. Mexico had yet to respond when Reuters reported the threat. President Claudia Sheinbaum was due to speak Thursday morning.

The dollar rose against the Mexican peso after the post, reaching about 18.68 pesos, MarketWatch reported.

What importers are watching

The U.S. imported $534.3 billion in goods from Mexico in 2025 and exported $337.3 billion there, according to the Census Bureau. Vehicles, machinery and medical devices are among Mexico’s leading exports to the United States. The U.S. Trade Representative also lists fresh vegetables, fruit and beer among Mexico’s agricultural exports to the U.S.

Duties on Mexican goods already vary by product and by whether the goods qualify for trade preferences under the United States-Mexico-Canada Agreement. A July U.S. Trade Representative notice, for example, imposed a 10% levy on covered Mexican products and exempted goods that qualified for duty-free treatment under the agreement. Separate sector tariffs apply to some goods, including vehicles and metals. Trump’s post left open which of those duties he meant to double and whether existing exemptions would carry over.

The threat came while Washington and Mexico City were negotiating on trade. Mexico has sought lower U.S. tariffs on cars, steel and aluminum in those talks, Reuters reported Wednesday. The U.S. declined to extend the North American trade agreement in its current form in July. It remains in force, and the trade office has started consultations for the next annual review in 2027.

For businesses bringing goods across the border, the details to watch are the covered products, any exemptions and the date customs begins collecting a higher duty. Those details are set out in the written trade action and customs instructions when a tariff takes effect.