West Palm Beach, Fla. — President-elect Donald Trump declared a win on stopping illegal immigration through Mexico on Wednesday after talking with that country’s leader. But Mexican President Claudia Sheinbaum suggested Mexico was already doing its part and had no interest in closing its borders.

The two spoke just days after Trump threatened to impose sweeping new tariffs on Canada and Mexico as part of his effort to crack down on illegal immigration and drugs — a threat that drew a prompt and terse response from Sheinbaum, who said any U.S. tariffs would be met with reciprocal measures from her government — stressing: “There is no subordination here.”

Sheinbaum said on Thursday she did not discuss tariffs in the call with Trump.

Trump said in his social media posts that Sheinbaum had “agreed to stop Migration through Mexico, and into the United States, effectively closing our Southern Border.”

Sheinbaum indicated on social media, however, that she’d “explained” to Trump that Mexico is already “taking care of” migrant caravans, calling it an “excellent conversation,” but indicating no major changes in her government’s policies.

“I explained to him the comprehensive strategy that Mexico has followed to address the migration phenomenon, respecting human rights. Thanks to this, migrants and caravans are assisted before they reach the border,” the Mexican leader wrote. “We reiterate that Mexico’s position is not to close borders but to build bridges between governments and between peoples.”

Trump’s social media posts about the borders — describing what he called “a wonderful conversation” with Sheinbaum and suggesting Mexico had made concessions in the wake of his tariff threat — did move financial markets.

Even if the proposed tariffs fail to materialize, Trump may argue to his supporters that the mere possibility of them is an effective policy tool, and continue to rely on tariff threats.

But the only new policy clearly referenced by either leader in their social media posts Wednesday was a vow by Trump to launch a new national ad campaign warning against the dangers of fentanyl use.

Sheinbaum had said in her message that she and Trump, “also talked about reinforcing cooperation on security issues, within the framework of our sovereignty, and the campaign we are carrying out to prevent fentanyl consumption.”

In his third, rapid-fire post on his own Truth Social platform about their conversation, the president-elect said he would be “working on a large scale United States Advertising Campaign, explaining how bad Fentanyl is for people to use — Millions of lives being so needlessly destroyed. By the time the Campaign is over, everyone will know how really bad the horror of this Drug is.”

On Massachusetts’ Nantucket island, where President Biden and his family are celebrating Thanksgiving, Mr. Biden while visiting a firehouse Thursday was critical of Trump’s plan.

“I hope he re-thinks it, I think it’s a counterproductive thing to do,” Mr. Biden told reporters.

The president warned against imposing tariffs on North American allies.

“We’re surrounded by the Pacific Ocean, the Atlantic Ocean, and two allies, Mexico and Canada. The last thing we need to do is begin to screw up those relationships,” Mr. Biden said.

Illegal migration across the Mexico border is down in part because the Biden administration secured some stepped-up cooperation from Mexico — the sort Trump seems to be celebrating.

Arrivals at the U.S.-Mexico border have dropped 40% from an all-time high last December. U.S. officials mostly credit Mexican vigilance around rail yards and highway checkpoints.

Driven by mounting pressure from the U.S. to block migrants going north, in the past few years Mexican authorities have turned to sending them to southern Mexico, in a strategy seen by experts as an attempt to wear migrants out until they give up.

Neither side clarified any firm plans to impose new tariffs in their social media messages on Wednesday. But their implementation could fuel higher prices for American consumers and slow economic growth, potentially blowing up the trade agreement among the U.S., Canada and Mexico that was finalized in 2020 during Trump’s previous time in the White House.

Trump on Monday said he would impose a 25% tax on all products entering the country from Canada and Mexico as one of his first executive orders upon taking office on Jan. 20. He also proposed an additional 10% tariff on China tied to its exporting of materials used in the production of fentanyl.

Through September, the United States has imported $378.9 billion in goods from Mexico, $322.2 billion from China and $309.3 billion from Canada.