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.

Reciprocal tariffs refer to tariffs—the taxes charged on imported goods—the U.S. government plans to levy against global trading partners that are equal to the existing tariffs foreign countries have set against American goods. “Very simply, it’s if they charge us, we charge them,” the President said on Sunday during a flight on Air Force One.