President Donald Trump raised the global duty on imports into the United States to 15 percent on Saturday. The announcement came one day after the Supreme Court ruled 6-3 that he overstepped his authority by imposing tariffs under a 1977 economic emergency powers act.

Trump made the declaration on his Truth Social platform. He described Friday’s court decision as an “extraordinarily anti-American” ruling. The administration hiked the levies to the “fully allowed, and legally tested, 15% level,” he wrote, following a review of the judgment.

The Supreme Court’s rebuke marked a rare defeat for Trump at the high court. Since returning to office 13 months ago, the justices have mostly backed his agenda. The decision invalidated his main tariff program, a cornerstone policy that disrupted global trade.

Friday’s initial response from Trump included a 10% global levy invoked through another legal avenue. He also lashed out at the conservative justices in the majority, accusing them of “disloyalty” and labeling them “fools and lap dogs.”

Trump praised the three dissenters—Justices Clarence Thomas, Samuel Alito, and Brett Kavanaugh, his nominee. He thanked them for their “strength and wisdom, and love of our country.” The president claimed the six-justice majority, including two from his first term, fell under “foreign interests” with “undue influence.”

The new 15% tariff applies temporarily for 150 days under the law. A White House fact sheet noted exemptions for sectors under separate investigations, such as pharmaceuticals. Goods entering under the US-Mexico-Canada agreement also escape the duty. Trading partners with individual deals still face the global rate, officials said Friday.

Sector-specific tariffs on steel, aluminum, and other goods remain unaffected. Ongoing government probes could trigger more targeted duties.

Trump’s tariff shifts have defined his economic approach over the past year. His team has repeatedly adjusted rates for various countries, creating volatility in trade relations with allies and adversaries alike.

Wall Street reacted calmly. Shares rose modestly Friday after the ruling, which markets had anticipated. Business groups welcomed the outcome. The National Retail Federation called it a source of “much-needed certainty” for companies.

The court did not rule on refunds for past tariffs. The Trump administration argued in hearings that firms would get money back if duties proved unlawful. Justice Kavanaugh warned any refund process could turn into a “mess.” Trump predicted years of lawsuits over the issue.

Saturday’s hike guarantees fresh trade tensions. Partners already strained by Trump’s policies now confront higher barriers across the board.