President Donald Trump, speaking to reporters on Air Force One Sunday, said he planned on announcing a 25% tariff on all steel and aluminum tariffs into the United States.

The president, who has threatened and delayed other tariffs, said he will announce the new measures Monday. Canada and Mexico are among the U.S.’s top steel suppliers.

President Donald Trump has said he will announce a 25% import tax on all steel and aluminium entering the US, a move that will have the biggest impact in Canada.