President Donald Trump has threatened to double tariffs on Mexico unless it stops migrant groups walking north towards the United States, warning in a social media post on Thursday that the migrants “will not be accepted”. The threat came after last week’s US midterm elections and while Washington and Mexico City were already in talks over trade.

Trump wrote on Truth Social: “Here we go again!” He added: “They will not be accepted! MEXICO MUST STOP THEM, NOW, and if they do not do so, the Tariffs on Mexico will be IMMEDIATELY DOUBLED.” He said Mexican officials, the governor of Texas, the Border Patrol and Immigration and Customs Enforcement (ICE) had been informed of his position, Reuters reported.

The caravan heading north

An estimated 1,500 people, mostly from Central America, set off on Tuesday from Tapachula, a city in southern Mexico near the Guatemalan border, according to Reuters. Spanish news agency EFE reported that the group initially numbered about 2,000 people. The migrants were said to be hoping that the Democrats’ victory in last week’s US midterm election could open new ways for them to live and work in the United States.

Tapachula sits at the far southern tip of Mexico, and groups that set off from there often break up long before they come anywhere near the US border. The journey north through Mexico is more than 1,000 miles, and Mexican immigration officials regularly intercept, disperse or return groups travelling in this way.

Mexico’s response

Mexican President Claudia Sheinbaum acknowledged on Thursday that a group of people was walking northwards, but said no migrant caravan had reached the US border since Trump returned to office in January 2025. She told her regular morning news conference that Mexico was informing the migrants how difficult it would be to enter the United States and was looking to return them to their countries of origin.

“There will be no acts of repression,” Sheinbaum said, according to Reuters. She said Mexican authorities were dealing with two groups in the country’s south. One group in Arriaga, in the southern state of Chiapas, had started with about 500 to 600 people and had fallen to fewer than 100 after migrants were told that reaching the United States would be extremely difficult. A second group had arrived from Honduras and was receiving humanitarian help and information about its options.

What Trump did not spell out

Trump did not say which tariffs he meant, what the new rates would be, or when any increase would take effect. No formal order putting higher duties in place had been confirmed by Thursday morning. FreightWaves reported that the warning raised the prospect of fresh disruption to North American trade and cross-border supply chains.

The Center Square reported that the administration imposed a 10% tariff on most Mexican goods in July under Section 301 of the Trade Act of 1974, and that doubling that duty would take it to 20%. The United States bought $481.6 billion in Mexican goods through September, more than from any other country, according to Census Bureau data cited in the same report. The Tax Foundation has estimated that tariffs now in place will cost the average US household about $820 this year, with about $130 of that linked to duties on Canadian and Mexican goods.

Trade talks already under way

The threat landed while the United States and Mexico were negotiating a trade agreement, after Trump chose in July not to extend the US-Mexico-Canada trade pact. The two sides have also been discussing possible reductions in US tariffs on steel, aluminium and cars, according to the Financial Times.

US Trade Representative Jamieson Greer was asked on CNBC’s “Squawk Box” on Thursday whether doubling Mexico’s tariffs was likely. He did not say. The US Trade Representative’s office also has a second Section 301 investigation open on Mexico.

Trump has used tariff threats against Mexico over migration before. In 2019 he threatened a 5% tariff on all Mexican goods, and Mexico agreed to send National Guard troops to its southern border before the tariff ever took effect.

Sources: Reuters, FreightWaves