Trump calls it unfair that some countries apply higher tariffs to specific American goods than the U.S. applies back. A new executive order seeks to change that.

WASHINGTON—President Trump ordered federal agencies on Thursday to explore how to adjust U.S. tariffs to match those of other countries, a move that threatens international rules in place for decades.

The president said his advisers would devise new tariff levels reflecting countries’ tariffs, taxes, subsidies and other policies affecting trade with the United States.