U.S, Feb. 20 -- Delivering a major blow to President Donald Trump's signature economic policy, the U.S. Supreme Court on Friday struck down most of the president's sweeping global tariffs.

The nation's highest court ruled in a 6-3 decision that the International Emergency Economic Powers Act, or IEEPA, does not authorize the president to impose tariffs.

"IEEPA contains no reference to tariffs or duties. The Government points to no statute in which Congress used the word 'regulate' to authorize taxation. And until now no President has read IEEPA to confer such power," Chief Justice John Roberts wrote in the majority opinion.

"We claim no special competence in matters of economics or foreign affairs. We claim only, as we must, the limite...