US President Donald Trump intensified a global trade war Wednesday as he slapped sweeping tariffs on imports from allies and foes alike, sending markets into a tailspin and upending decades-long free trade norms.

The EU and China vowed retaliation against the levies, with Australia's leader saying the new tariffs were "not the act of a friend" and would hurt the close allies' relationship.

Shortly after Trump's proclamation, separate tariffs of 25 percent on all foreign-made cars and light trucks went into effect, with auto parts also due to be hit by May 3.

Holding up a chart of the sweeping measures in the White House Rose Garden, Trump unveiled particularly stinging tariffs on major trade partners China and the European Union on what he called "Liberation Day."

"This is one of the most important days, in my opinion, in American history," said Trump. "It's our declaration of economic independence."

The tariffs announcement triggered immediate anger around the world, with rival China warning they could "endanger" global economic development.

Stock markets looked set for major........

© International Business Times