President Trump on Sunday said that he would impose a 25 percent tariff on all foreign steel and aluminum imports into the United States as of Monday and would soon announce reciprocal tariffs on America’s trading partners.

Speaking from Air Force One en route to the Super Bowl, the president said his metal tariffs would apply to “everybody,” including Canada and Mexico, America’s allies and its largest trading partners.

“Any steel coming into the United States is going to have a 25 percent tariff,” Mr. Trump said. “Aluminum, too.”

Mr. Trump’s decision to tax foreign metals and impose reciprocal tariffs comes in the wake of several other trade threats he has made since winning the White House.

Since taking office, Mr. Trump has imposed an additional 10 percent tariff on all products from China, and came within hours of imposing sweeping tariffs on Canada and Mexico that would have brought U.S. tariff rates to a level not seen since the 1940s.

Mr. Trump has also said in recent days that he planned to impose tariffs on Europe, Taiwan and other governments, as well as on a variety of critical industries like copper, steel, aluminum, pharmaceuticals and semiconductors.

The decision to impose tariffs on metals would affect some of America’s biggest trading partners and allies.

The largest supplier of steel to the United States in 2024 was Canada, followed by Brazil, Mexico, South Korea and Vietnam, according to the American Iron and Steel Institute. Canada is also a major supplier of aluminum to the United States, followed distantly by the United Arab Emirates, Russia and China.

Mr. Trump’s decision to impose tariffs on metals is not new. In his first term, the president levied tariffs on foreign steel and aluminum globally, angering allies like Mexico, Canada and the European Union. He ultimately rolled back some of those barriers on Canada and Mexico when they signed a revised trade agreement with the United States.

The Biden administration later reached agreements with the European Union, the United Kingdom and Japan to roll back some of their trade restrictions. A handful of other countries also negotiated quotas or other arrangements, but for most countries the steel and aluminum tariffs remain in place, said Chad Bown, a senior fellow at the Peterson Institute for International Economics. It’s not clear if the new tariffs would be added to the old ones.

Both of Mr. Trump’s new tariff proposals would broaden his trade fight to many different countries, setting off trade spats that could encourage other countries to retaliate with their own tariffs on American goods.

Mr. Trump has already rocked diplomatic and economic relationships over the past week with almost-daily tariff threats.

The reciprocal tariffs the president has proposed would raise the levies the United States charges on certain imports to match what other countries charge on American products when those goods come across their borders. They could be used by the president as a lever to seek further concessions in negotiations. But they would also violate U.S. commitments to the World Trade Organization.

The president said his reciprocal tariffs would be announced on Tuesday or Wednesday at a news conference, and the tariffs would go into effect “almost immediately” on every country.

“Very simply, if they charge us, we charge them,” he said.