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.

The promised tariffs on steel and aluminium come as Trump has launched his second term with an aggressive trade policy. Last week he came within hours of setting 25 per cent tariffs on imports from US neighbours Canada and Mexico, only to offer them a 30-day reprieve.

President Donald Trump says he will also impose "reciprocal tariffs" on any countries who place tariffs on the US.

The US president also said he will announce reciprocal tariffs on Tuesday or Wednesday, to take effect almost immediately, applying them to all countries and matching the tariff rates levied by each nation.

Canada will keep trying to persuade the Trump administration to drop its tariff plans, in part by reaching out to US states that have significant trading relationships with their northern neighbor, trade minister Mary Ng said.

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. Trump also said that there would be an announcement later in the week about reciprocal tariffs on all countries that tax imports from the US,

US President Donald Trump signed an executive order on Friday delaying tariffs on lower-value packages from China that enjoy the exemptions until the US Commerce Department can confirm that procedures and systems are in place to process packages and collect tariff revenue.

U.S. President Donald Trump is set to announce a 25 per cent tariff on all steel and aluminum imports on Monday, including those from Canada. Trump, once again, expressed a desire to make Canada the 51st state.