The rulings against the levies in two federal courts – the U.S. Court of International Trade and the U.S. District Court in Washington, D.C. -- centered on Trump's unprecedented invocation of the International Economic Emergency Powers Act as a legal justification for tariffs.

President Donald Trump warns of economic ruination if courts rule against his tariffs after the U.S. Court of International Trade blocks emergency import taxes.

The court said Mr. Trump's global 10% tariffs aren't authorized by IEEPA because they're designed to deal with trade imbalances between the U.S. and the rest of the world, which the judges said should fall under non-emergency legislation.