U.S. President Donald Trump said he would impose reciprocal tariffs as soon as Wednesday evening on every country that charges duties on U.S. imports, in a move that ratchets up fears of a widening global trade war and threatens to accelerate U.

Senior aide Peter Navarro is a driver of the idea inside the White House. He pushed for reciprocal tariffs during Trump’s first term.

European officials criticized trade wars as bad for businesses and consumers on both sides but insisted they would safeguard their own interests.