Donald Trump has vowed to impose a 10 per cent “global tariff” using an alternative law after the Supreme Court ruled that his sweeping duties are illegal.
In a press conference following Friday’s landmark rebuke from America’s top court, Trump said: “Other alternatives will now be used to replace the new ones that the court incorrectly rejected.”
“We have alternatives, great alternatives could be more money, we’ll take in more money,” he added.
Trump said he would impose a 10 per cent levy on top of existing US tariffs, using the Trade Act of 1974, which allows the president to set import restrictions for up to 150 days.
It was not immediately clear which existing duties the president was referring to.
Earlier on Friday, the Supreme Court ruled in a 6-3 vote that Trump exceeded his authority in using the International Emergency Economic Powers Act to impose tariffs on dozens of countries.
The decision marked the first significant defeat for Trump at the court, after it handed the president several wins in previous cases including on the deportation of migrants.
In its ruling, the Supreme Court said: “Our task today is to decide only whether the power to ‘regulate . . . importation’, as granted to the President in IEEPA, embraces the power to impose tariffs. It does not.”
Trump on Friday lashed out at the decision, saying it was “deeply disappointing and I’m ashamed of certain members of the court”.
The verdict, which covers the majority of the duties imposed by the White House, also threatens to cause major disruption for America’s trading partners and companies across the world.
Chief Justice John Roberts wrote the opinion for the majority. Justices Clarence Thomas, Samuel Alito and Brett Kavanaugh dissented.
The Supreme Court did not rule on whether the US must refund revenue raised from the duties.
In his dissenting opinion, Kavanaugh wrote: “The Court says nothing today about whether, and if so how, the Government should go about returning the billions of dollars that it has collected from importers.”
The case was brought by groups of American businesses, joined by 12 US states, that argued they had been harmed by the tariffs.
In its ruling, the court said that in “IEEPA’s ‘half century of existence’, no President has invoked the statute to impose any tariffs — let alone tariffs of this magnitude and scope.”
Trump announced his tariff regime on “liberation day” last April, sparking weeks of turmoil in financial markets and alarming US allies.
Although he has since backed away from imposing some of the most severe duties, the US ended 2025 with an effective tariff rate of more than 10 per cent — the highest since the second world war.
The ruling drew a muted reaction from investors, with the US dollar index down 0.1 per cent. The S&P 500 and Nasdaq Composite were up 0.4 per cent and 0.8 per cent, respectively.
Jason Borbora-Sheen, a portfolio manager at Ninety One, said the response indicated that the outcome was “largely expected . . . and the administration has had a while to plan their reaction”.
Stock markets have recovered since “liberation day” to hit record highs, but polls indicate that many Americans think the tariffs are hurting the country’s economy.