President Trump’s tariffs have changed numerous times since they were announced in April, as foreign leaders negotiate and try to secure exemptions.

Most of the new duties kicked in Thursday, hitting countries with elevated rates that mark a departure from long-standing trade norms.

The U.S. has concluded trade frameworks with top trading partners including the European Union, Japan and South Korea. But deals with others remain works in progress, and Trump is also targeting specific industries like semiconductors that are used by millions of Americans across a wide range of products.