Stocks were tumbling across the Atlantic on Tuesday after U.S. President Donald Trump's tariffs on Canada and Mexico took effect, stoking investors' fear that Washington could soon impose similar levies on the European Union.

U.S. President Donald Trump's new 25% tariffs on imports from Mexico and Canada took effect on Tuesday, along with a doubling of duties on Chinese goods to 20%, launching new trade conflicts with the top three U.

Starting just past midnight, imports from Canada and Mexico are now to be taxed at 25%, with Canadian energy products subject to 10% import duties.

Mexico is expected to announce its response later.The three major stock market indexes in the US sank following the news, while the FTSE 100 index of the UK's biggest publicly-listed companies opened sharply lower on Tuesday and stock markets in Asia were also down.

President Donald Trump delivered on his threat to hit Canada and Mexico with sweeping import levies, imposing one of the largest increases in US tariffs since the 1930s in a dramatic escalation of a trade war that stands to upend ties with major economic partners.

Shares were mixed Tuesday in Asia after U.S. stocks fell sharply just ahead of a new round of higher tariffs imposed by U.S. President Donald Trump, which China hit back at with higher duties on U.S.

President Donald Trump's tariff actions, which could upend nearly $2.2 trillion in two-way annual U.S. trade, went live on Tuesday.