WASHINGTON — Markets and foreign capitals have braced themselves for a broad set of tariffs from President Trump on Wednesday, anxious for details on a dramatic shift in U.S. trade policy that is expected to supercharge the costs of cars, houses and everyday goods for Americans.

It is unclear whether the Trump administration plans to impose a universal, baseline rate for import taxes on trading partners, or to customize tariff policy to each foreign nation, imposing “reciprocal” rates on a case-by-case basis. It is also unclear whether there will be any exceptions. A White House official told The Times that exact details of the plan are “still being perfected.”

The lack of clarity has rattled markets in recent weeks, driving the worst first annual quarter in three years and erasing gains on the Standard & Poor’s 500 index made since Trump’s election victory in November.

The White House said Trump would announce his plans at 1 p.m. Pacific time on Wednesday, precisely when closing bells ring on Wall Street.

After that, the new policy will be “effective immediately,” White House Press Secretary Karoline Leavitt told reporters at a Tuesday news briefing.

Costs could rise immediately on perishable goods caught in limbo at international ports, including avocados and pineapples, said Sung Won Sohn, a former commissioner at the Port of Los Angeles. Prices on larger items with dwindling inventories, such as foreign cars and washing machines, are likely to rise within weeks.

Lumber is stacked outside at the Milan Lumber Co. in Milan, N.H.

(Robert F. Bukaty / Associated Press)

For Los Angeles, in particular, the tariffs are “coming at a very bad time,” Sohn said. “We’re in kind of bad shape, because you need a lot of lumber to rebuild from the fires, and the construction hasn’t started yet. It’ll probably start in three to four months, and that’s exactly when we’re going to be hit by higher prices for lumber.”

Top European Union leaders have alluded to potent retaliation that could extend beyond American whiskey and hit directly at Silicon Valley, core to the U.S. and Californian economy. And California’s agricultural economy — the nation’s largest — could become a target as well.

Retaliatory tariffs are expected to come from nations across the world affected by the new rates, risking further response from the Trump administration, thus prompting a spiral into a trade war with few winners.

Leaders in Canada, the second largest U.S. trading partner, have said Ottawa will react swiftly to any new tariff actions. But Mexican President Claudia Sheinbaum suggested Tuesday that her administration will not retaliate immediately if Washington slaps new taxes on Mexican imports.

“We don’t believe in an eye for an eye, a tooth for a tooth, because that always leads to a bad situation,” Sheinbaum told journalists at her daily news conference.

Mexican President Claudia Sheinbaum addresses supporters at a March 9, 2025, rally at the Zocalo, Mexico City’s main square.

(Eduardo Verdugo / Associated Press)

Instead, she called for further negotiations with the U.S., even while acknowledging that she has no plans to speak to Trump in the coming days.

“The dialogue must continue,” Sheinbaum said. “It’s not a matter of ‘You put that, so I’ll put that,’ but rather what’s best for Mexico.”

‘Shorter-term pain’

Trump’s advisors say the new policy will bring about an overdue correction, returning fair trade practices, ultimately raising significant revenue for the federal government and bringing back manufacturing to U.S. shores.

It is, in many ways, the culmination of a years-long campaign by Trump to increase tariffs going back to the 1980s, when as a real estate developer and celebrity, he accused Japan and China of “laughing at” and “ripping off” the United States.

In his address to a joint session of Congress on March 4, Trump complained that countries across the globe place tariffs on U.S.-made goods. “On average, the European Union, China, Brazil, India, Mexico, and Canada — have you heard of them? — and countless other nations charge us tremendously higher tariffs than we charge them. It’s very unfair,” he said.

In his first term, Trump negotiated a detailed trade deal, the United States-Mexico-Canada Agreement, that replaced the North American Free Trade Agreement and governed trade practices among the United States and its closest trading partners.

Susano Cordoba sells peanuts to truck drivers lining up in Tijuana to cross the border into the United States on March 4, 2025.

(Gregory Bull / Associated Press)

But since resuming office in January, Trump has repeatedly threatened new rounds of tariffs on Mexican and Canadian goods, often retreating from his plans at the last moment.

The “on-again, off-again” threat of tariffs have contributed to the instability jolting stock markets, which closed on Tuesday slightly up after a day of volatile trading.

Allies of the White House have acknowledged that short-term “pain” can be expected for U.S. households in the wake of the new policy implementation, which Trump has referred to as “Liberation Day.”

“There’s absolutely going to be short-term pain,” Republican Sen. Tim Sheehy of Montana told CNN on Monday. “The president’s been clear about that. Everyone has.”

“If you’re going to remodel your house to make it better in the end, it’s going to be really annoying in the short term, when your house is getting remodeled and there’s drywall dust everywhere and there’s workers in your living room,” Sheehy added. “The reality is that remodel’s got to happen in order to make things stronger and more stable in the back end.”

Already, American consumers have begun to cut back on their spending and boost their savings. A Friday report from the Bureau of Economic Analysis, a government agency, showed that the personal savings rate rose 4.6% in February. Consumer spending increased just .4%, after decreasing by .3% in January.

Leavitt added Tuesday that many countries have been calling the president, asking for relief from the anticipated tariffs. She said the president is open to taking their calls.

“It’s simple: If you make your product in America, you will pay no tariffs,” Leavitt said.

It is unclear how the administration will measure the success of the new tariffs. Leavitt called the stock market, which has experienced volatility in recent weeks over tariff turmoil, a “snapshot in time.” The White House has repeatedly pointed to companies that have newly invested in the U.S. since Trump took office as evidence of tariffs working.

A pause on other 25% tariffs against Canada and Mexico is also set to expire Tuesday, and the White House would not confirm whether it would be lifted.

Trump’s announcement comes the same day that 25% tariffs were set to take effect on auto imports at 12:01 a.m. Wednesday.

Times staff writer Kate Linthicum in Mexico City contributed to this report.