The president has ratcheted up the rate on foreign metals to 50 percent, double the previous rate, saying the levies weren’t high enough to help the U.S. industry.

The president first announced the doubling of tariffs on aluminum and steel at a rally in Pennsylvania last week.

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.

Officials from the European Union and the United States will start a new negotiating push, after President Trump delayed until July 9 tariffs of 50 percent.

By Tom Käckenhoff and Christoph Steitz DUESSELDORF/FRANKFURT (Reuters) -Salzgitter, Germany's second-biggest steelmaker, on Monday warned that Washington's tariff policy was dealing a severe blow to European industry,

Despite promised blowback from Europe, Donald Trump formally raised steel and aluminum tariffs to 50% from 25% on Tuesday. The move by the president raises trade tensions at a time when the US is locked in negotiations with numerous trading partners over his so-called “reciprocal” duties before a July 9 deadline.