These customized levies, expected to be finalized by April, are designed to rebalance trade relationships and target unfair practices, including subsidies, regulations, and exchange rate manipulation.

President Donald Trump is taking a blowtorch to the rules that have governed world trade for decades. The “reciprocal’’ tariffs that he announced Thursday are likely to create chaos for global businesses and conflict with America’s allies and adversaries alike.

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.