www.bbc.co.uk/news/articles/c627nx42xelo
Summary of tariffs and why Trump says he wants to impose them.
"The US president said the move was in response to his concerns about illegal immigration and drug trafficking - two of the main promises on which he was elected.
Trump posted on his Truth Social platform: "This was done through the International Emergency Economic Powers Act (IEEPA) because of the major threat of illegal aliens and deadly drugs killing our Citizens, including fentanyl."
Trump has indicated he is ready to escalate the duties further if the countries retaliate."
As an. example, Trudeau's response
"We don't want to be here, we didn't ask for this," he said at a news conference late on Saturday.
"But we will not back down in standing up for Canadians."
His government will impose 25% tariffs on $155bn worth of American goods - $30bn will come into force on Tuesday and another $125bn in 21 days.
Targeted items include American beer, wine, bourbon, fruits and fruit juices, vegetables, perfumes, clothing and shoes, as well as household appliances, sporting goods and furniture. Lumber and plastics will also face levies.
Non-tariff measures being considered are related to critical minerals and procurement, although Trudeau did not offer more detail.
The Canadian prime minister pushed back on the suggestion the shared border posed a security concern, saying less than 1% of fentanyl going into the United States comes from Canada.
Canada is America's largest foreign supplier of crude oil. According to the most recent official trade figures, 61% of oil imported into the US between January and November last year came from Canada."