By Dietrich Knauth, Blake Brittain NEW YORK (Reuters) -Five American small businesses asked a U.S. court on Tuesday to halt President Donald Trump's "Liberation Day" tariffs, arguing that he overstepped his powers by declaring a national emergency to impose across-the-board taxes on imports from nations that sell more to the United States than they buy.

The nonpartisan Liberty Justice Center filed the lawsuit on behalf of five small U.S. businesses that import goods from countries targeted by the duties. The companies, which rang