President Donald Trump revealed his most sweeping economic measure yet Thursday, announcing reciprocal tariffs that could come as soon as this spring, which Trump argues would level the playing field in global trade—though economists project they would increase inflation this year.

White House aides confirmed that they expect foreign nations to negotiate down Trump’s reciprocal taxes by lowering their import fees on U.S. goods. The White House did not say if Trump would consider dropping tariffs in exchange for non-trade-related concessions.

Since the 1960s, tariffs — or import taxes — have emerged from negotiations between dozens of countries. Trump wants to seize the process. “Obviously, it disrupts the way that things have been done for a very long time,