PALM BEACH, Fla. — President Trump on Saturday imposed significant tariffs on Canada, Mexico and China, a White House spokesperson said, following through on a long-standing pledge and potentially setting off a trade war with the United States’ top trading partners.

“Tariffs on imports from Canada, Mexico, and China are SIGNED!” White House spokesperson Harrison Fields posted on X. “This bold move holds these countries accountable for stopping illegal immigration and the flow of dangerous drugs like fentanyl.”

Trump is imposing a 25 percent tariff on imports from Mexico and Canada, as well as a 10 percent tariff on Chinese goods. Canadian energy imports will only be tariffed at 10 percent. The tariffs are set to take effect on Tuesday.

The tariffs signed Saturday include a clause that stipulates the U.S. could increase the tariffs if any of the countries retaliate, which they are expected to do.

For months, the president has vowed to impose tariffs on the three countries as he called on them to do more to crack down on the flow of migrants and fentanyl into the United States.

Trump has signaled Saturday’s announcement may just be the first step in imposing widespread tariffs, potentially setting off a cascading trade war. Trump told reporters Friday he would announce tariffs in the coming weeks on steel and aluminum, pharmaceuticals, oil and gas, semiconductor chips and imports from the European Union broadly.

Experts have repeatedly warned that tariffs could lead to higher costs that companies will pass onto consumers. 

The Tax Foundation, a nonpartisan think tank, estimated Trump’s tariffs announced Saturday would result in what amounts to an average tax increase of $830 per household in the U.S.

Sen. Susan Collins (R-Maine) warned in a statement late Friday that certain tariffs on Canadian imports “will impose a significant burden on many families, manufacturers, the forest products industry, small businesses, lobstermen, and agricultural producers.”

While Trump has acknowledged there could be “short-term” disruptions because of his tariffs, he has insisted they will strengthen the economy in the long term by bringing back domestic production.

Mexico and Canada have promised swift and thorough retaliation in recent weeks as Trump has threatened tariffs. Trump initially promised tariffs on the first day of his presidency, but later moved the date back to Feb. 1.

Canadian Prime Minister Justin Trudeau was expected to announce the country’s response on Saturday night, according to CTV.

Ontario premier Doug Ford said Friday that Canada was ready for a trade fight.

“[Trump] sat in his oval office and mused about tariffs on Canada. He says they’re coming tomorrow,” Ford said. “Retaliatory tariffs by the federal government are the tip of the spear … Canada has so much of what America needs, what their military and economy depend on – high grade nickel and other critical minerals.”

Retaliatory tariffs during the first Trump trade war in 2018 with China were targeted largely at agri-business.

“Agriculture is generally the first target generally because there are other sources,” Bill Reinsch, chair of international business at the Center for Strategic and International Studies, told The Hill. “It strikes at one of the strongest areas of Trump’s support. In 2018, what he ended up having to do was, he basically bought off all the farmers.”

Another sector that could be hit hard by the tariffs is autos. Auto production has been integrated across U.S., Canadian and Mexican borders since the big international trade deals of the 1990s.

“The biggest loser … will be the auto industry because so many things go back and forth so many times. If they charge a tariff every time something crosses a border, you’re talking about something that adds up very quickly,” Reinsch said.

Tobias Burns contributed. Updated at 5:31 p.m. EST