U.S. appeals court judges sharply questioned on Thursday whether President Donald Trump's tariffs were justified by the president's emergency powers, as lawyers for states and businesses challenging the measures argued he exceeded his authority.

An appeals court in Washington will consider President Donald Trump's sweeping tariff plan, which comes into force Aug. 1, and has sparked consternation from small businesses.

A panel of appeals court judges on Thursday voiced deep skepticism with the Trump administration's attempt to justify sweeping tariffs based on a national emergency.