President Donald Trump affirmed on Thursday that imports from U.S. allies Mexico and Canada will be hit with a 25 percent tariff starting on Saturday. Speaking to the press from the Oval Office, Trump said that his administration will follow through in announcing tariffs on America’s neighboring countries for “a number of reasons”—chiefly among them being an alleged influx of migrants at the U.

The emergency tariffs were set to take place on Tuesday, and the deals offer temporary relief amid concerns about higher costs globally.

The tariffs, which also target China, are scheduled to go into effect Tuesday. They prompted immediate efforts to retaliate.