He has said he will announce a 25% import tax on all steel and aluminum entering the US, a move that will have the biggest effect 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, but he did not specify which nations would be targeted, or if there would be any exemptions.
"If they charge us, we charge them," Trump said.
The move marks another escalation in Trump's trade policy , which has already sparked retaliation from China.
The effect on the UK is expected to be small because it does not import or export much steel to the US.
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By contrast, Canada and Mexico are two of the US's biggest steel and aluminum trading partners.
Steel production in the US is heavily politicized. Some argue the country needs to be capable of producing enough high quality steel to supply its military in the event of a national emergency without relying on imports.
During his first term, Trump put tariffs of 25% on steel imports and 10% on aluminium imports from Canada, Mexico and the European Union.
But the US reached a deal a year later with Canada and Mexico to end those tariffs, although the EU import taxes remained in place until 2021.
Those tariffs increased costs for makers of fizzy drinks and cars in the US and these were then passed onto consumers, according a report from thinktank Tax Foundation.
Talking aboard Air Force One, Trump said on Monday he would announce tariffs on "everybody" for steel and aluminum.
"Any steel coming into the United States is going to have a 25% tariff," he said.
In response, Doug Ford, the premier of the province of Ontario, accused Trump of "shifting goalposts and constant chaos, putting our economy at risk" in an online post. Canada's steel production is concentrated in Ontario.