President Donald Trump's threats to impose high tariffs on countries make U.S. trading partners and investors nervous. But his sector tariffs could hurt consumers and businesses more in the long run.

President Donald Trump said he planned to implement a 50% duty on copper imports as part of a set of looming sectoral tariffs, while also indicating he could offer pharmaceutical manufacturers at least a year before applying a crippling 200% tariff on their foreign-made products.

Copper prices surged and the Dow industrials slipped on Tuesday after President Trump announced a surprisingly large tariff on imports of the metal, and declared that he would hold firm on his latest deadline for trade deals with foreign countries.