MEXICO CITY — One day after President Trump’s sweeping tariffs took effect, ending decades of free trade across North America, Mexicans reacted with a mix of fear and defiance.

“There will not be submission,” President Claudia Sheinbaum said at her daily news conference Wednesday. “Mexicans are valiant and strong.”

Sheinbaum reiterated her plan to announce punitive counter measures — including taxes on some U.S. imports — at a public event in Mexico City on Sunday.

It was unclear whether Mexico’s response would be tempered by the White House announcement Wednesday that automakers would be exempted from the newly imposed tariffs for one month.

Already on Wednesday, the impact of the tariffs was being felt.

At the border, business leaders reported an immediate drop in the quantity of goods crossing north to the U.S. as companies on both sides sought to avoid the new taxes.

In the streets of the nation’s capital, there was a palpable sense of unease.

While the peso has largely held strong against the dollar, there are real fears about what a trade war would mean for Mexico, whose economy depends heavily on commerce with the United States, sending 80% of its exports there.

Noah Espinosa, a 43-year-old dentist in Mexico City, said he worried about rising prices.

“Whatever Trump does, the dollar immediately goes up and everything in Mexico becomes more expensive,” Espinosa said. “The dollar goes up and so do tortillas, the dollar goes up and so does meat.”

He said many of the products he uses in his dental practice come from the United States, too.

“The worst thing,” he said, “is that it seems that Trump does not care about destroying our economy and the economy of his own country, as long as he feels like the most powerful man in the world.”

For many, the specter of an economic crisis brought back memories of another one, during the mid-1990s, when the sudden devaluation of the peso sparked a severe recession and contributed to some 5 million Mexicans immigrating to the U.S.

“From one day to the next, we lost everything,” said Ricardo Aguilar, 65, who owns a hardware store in the Cuajimalpa neighborhood.

“Now that Trump is making these threats, those memories come back to my mind and make me want to cry,” Aguilar said. “Without economic stability, you lose everything: your health, your peace of mind. There is more violence; everything gets complicated.”

“I hope to God that we don’t have to live through a crisis of that magnitude again,” he said. “But Trump is very emboldened.”

The tariffs took effect Tuesday morning. Overnight, Washington began levying a 25% tax on all products imported from Mexico and Canada, with the exception of Canadian oil and gas, which are subject to a 10% tariff. Trump also imposed a new 10% tax on imports from China.

Canada and China immediately announced retaliatory taxes on U.S. goods — Canadian Prime Minister Justin Trudeau called the tariffs “very dumb” — and Mexico said it would soon announce its own counter-tariffs.

Speaking to the U.S. Congress Tuesday night, Trump echoed a promise he made earlier in the day that he would respond to any retaliatory taxes with another set of tariffs.

President Trump claps as he addresses a joint session of Congress at the Capitol in Washington on Tuesday night.

(Ben Curtis / Associated Press)

“Whatever they tariff us, we tariff them,” he said. “Whatever they tax us, we tax them.”

Trump has cited several reasons for imposing tariffs: the flow of illegal drugs and migrants across the U.S. border; his desire to bring manufacturing back to America; his anger over the trade imbalance that the U.S. has with most nations.

“We’ve been ripped off for decades by nearly every country on earth and we will not let that happen any longer,” he said.

In Mexico, there was deep frustration that Trump had not recognized the country’s considerable efforts on security and migration in recent months. Mexico has helped bring illegal border crossings to the lowest levels in years — and has increased seizures of fentanyl, the synthetic opioid that has caused tens of thousands of U.S. deaths.

“Trump is a liar, he said there would be no tariffs if we put a stop to migration,” said Maria Esther Garcia, 51, a homemaker.

She said she hoped Sheinbaum would stop trying to appease the Americans.

“It’s no use because Trump is not a man of honor,” Garcia said. “President Sheinbaum should not trust him. It’s better for us to look for other countries for our Mexican avocados.”

Jorge Lara, a 37-year-old computer technician, said that while Mexicans would be affected by tariffs, harder hit would be American consumers, who will likely soon start paying higher prices for agricultural goods.

He hoped that they would would pressure Trump to reverse course.

“As soon as the Americans begin to suffer from high prices in their country, they will react against their government, and Trump will have no choice but to eliminate the taxes,” Lara said.

In his address Tuesday to Congress, Trump repeated his charge that Mexico is completely under the sway of organized crime — an assertion that Sheinbaum has repeatedly refuted as a calumny.

“The territory to the immediate south of our border is now dominated entirely by criminal cartels that murder, rape, torture and exercise total control,” Trump told Congress. “They have total control over a whole nation, posing a grave threat to our national security.”

Still, Trump lauded Mexican authorities for their decision last week to hand over 29 alleged cartel operatives, including Rafael Caro Quintero, alleged mastermind of the 1985 slaying in Mexico of Drug Enforcement Administration agent Enrique “Kiki” Camarena.

The president explicitly linked the hand-off of the 29 suspects — all wanted in the United States — to his tariff policies.

“That has never happened before. They want to make us happy. First time ever,” Trump said of Mexican officials’ decision to turn over the 29 suspects to U.S. law enforcement. “But we need Mexico and Canada to do much more than they’ve done, and they have to stop the fentanyl and drugs pouring into the USA.”

Times special correspondent Cecilia Sánchez Vidal and staff writer Patrick McDonnell contributed to this report.