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.

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.

A panel of appeals court judges bombarded a Trump administration attorney Thursday with pointed questions about the president’s use of emergency powers to levy reciprocal tariffs on dozens of countries — hours before “Liberation Day” duties were set to take effect.