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.

Trump has pledged to punish Canada and Mexico for “bringing Crime and Drugs at levels never seen before” by imposing a 25 percent tariff on all imported goods from U.S. neighbors — with no exceptions made for oil and natural gas.

The proposed tariffs, if applied to oil and gas, could hammer Canada's economy and hike prices at the pump for Americans, analysts say.

President-elect Donald Trump's proposed 25% tariff on goods from Mexico and Canada would harm relations between the United States and Mexico and Canada, President Joe Biden told reporters on Thursday.

Mexico's President Claudia Sheinbaum said on Thursday she did not specifically discuss tariffs in a call with U.S. President-elect Donald Trump a day earlier, after Trump threatened a 25% import tax that appears to contravene a free trade pact.