U.S. appeals court judges sharply questioned on Thursday whether President Donald Trump's tariffs were justified by the president's emergency powers, after a lower court said he exceeded his authority with sweeping levies on imported goods.

U.S. appeals court judges challenge President Trump's use of emergency powers to impose broad tariffs. The court examines the legality under the International Emergency Economic Powers Act, with opposing legal arguments highlighting constitutional concerns.

On the day before President Donald Trump's next set of tariff hikes is set to materialize, a federal appeals court will grapple with the big, unanswered question underpinning the president's aggressive and unprecedented trade policies.