The president urged his successor to reconsider his threats to impose sweeping tariffs on Canada and Mexico, warning they could undermine relations with two of the U.S.’s closest allies.

Trump said in a post to Truth Social on Monday that one of his first executive orders would be to hit Mexico and Canada with a blanket 25% tariff. Mexico and Canada are the second and third top suppliers of goods to the U.S., according to the Office of the U.S. Trade Representative. The U.S. imports the most goods from China.