Donald Trump's trade advisers were finalizing plans on Wednesday for the reciprocal tariffs the U.S. president has vowed to impose on every country that charges duties on U.S. imports, ratcheting up fears of a widening global trade war.

President Donald Trump could announce his most sweeping tariffs yet Wednesday, unveiling reciprocal tariffs that Trump argues would level the playing field for the U.S. in global trade and would instantly become the hallmark economic policy of his nascent second term, though economists project they would increase inflation this year.

“Any steel coming into the United States is going to have a 25% tariff,” he told reporters Sunday on Air Force One as he flew from Florida to New Orleans to attend the Super Bowl. When asked about aluminum, he responded, “aluminum, too” will be subject to the trade penalties.