US President Donald Trump has signed an order doubling tariffs on steel and aluminium imports from 25% to 50%. The move hikes import taxes on the metals - key inputs in everything from cars to canned food - for the second time since March.

President Trump doubles steel and aluminum tariffs to 50% starting June 4 to protect U.S. industries and national security.

US tariffs of 50 per cent on steel and aluminium will take effect from June 4 after Donald Trump signed an executive order on Tuesday escalating his global trade war. The new tariffs double existing levies of 25 per cent that the president introduced earlier this year.