President Donald Trump signed a memo Thursday directing his administration to start determining what level of reciprocal tariffs the U.S. will impose on foreign imports—after long promising to announce the new round of tariffs—but the new taxes will not take effect yet.

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

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.