The Yale Budget Lab noted that the letters sent Monday would hike the effective tariff rate on U.S. consumers to the highest since 1934.

WASHINGTON (Reuters) -President Donald Trump said he will announce a 50% tariff on imported copper on Tuesday, an effort to boost U.S. production of a metal critical to electric vehicles, military hardware, the power grid and many consumer goods. U.S. Comex copper futures jumped more than 10% after the announcement.

President Donald Trump said a new 50% tariff on all copper imports will come Tuesday. However, he did not specify when the new tariff would take effect.