President Donald Trump moved to substantially raise tariffs on steel and aluminum imports on Monday, cancelling exemptions and duty-free quotas for major suppliers Canada, Mexico, Brazil and other countries in a move that could boost the risk of a multi-front trade war.

Steel and aluminum are heavily used in the automotive and construction industry, but are also used to manufacture goods and appliances. The decision mirrors the actions Trump levied during his first Administration, when he enacted a 25% tariff on steel and 10% tariff on aluminum, though some countries, including South Korea were exempt.

Trump's decision to include downstream finished products is a significant move that will have broad-reaching price impacts on a massive swath of US consumers

President Donald Trump ordered a 25% tariff on steel and aluminum imports, escalating his efforts to protect politically important US industries with levies hitting some of the country’s closest allies.

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

Starting Tuesday, nearly all imports from Canada and Mexico will be charged a 25% tariff, while goods from China will be charged a 10% tariff.

Shares in European and Asian steelmakers fell on Monday after U.S. President Donald Trump said he would introduce 25% tariffs on all steel and aluminium imports within hours in addition to existing metals duties.

President Trump says he plans to impose a new 25% tariff on steel and aluminum imports including from Canada and Mexico.