US President Donald Trump on Saturday raised the United States’ global import tariff to 15%, escalating his trade agenda just one day after the Supreme Court of the United States ruled much of his tariff authority illegal.

Announcing the move on Truth Social, Trump said the increase followed a review of what he called the court’s “extraordinarily anti-American decision,” stressing the new rate was “fully allowed” under alternative legal powers.

The decision comes after a 6–3 Supreme Court ruling blocked his use of a 1977 economic emergency law to impose sweeping tariffs. Trump initially announced a 10% global levy, before quickly raising it to 15% and launching a blistering attack on conservative justices who sided with the majority, branding them “disloyal” and “lap dogs.”

The ruling marked Trump’s biggest legal setback since returning to office, striking at a core pillar of his economic policy that has reshaped global trade and rattled US allies and rivals alike.

The White House confirmed the new tariff will apply for up to 150 days, with exemptions for goods covered under the US-Mexico-Canada Agreement and sectors under separate investigations, including pharmaceuticals. Countries that previously struck individual trade deals with the administration will also be subject to the new rate.

While tariffs on steel and aluminum remain untouched, officials warned further sector-specific duties could follow. Trump praised Justices Clarence Thomas, Samuel Alito, and Brett Kavanaugh for backing him, while accusing the majority of being influenced by “foreign interests.”