US allies line up for exemptions from Donald Trump's tariffs on imports

Tokyo and Brussels rejected any suggestion that their exports to the United States threatened its national security - Trump's justification for imposing the tariffs despite warnings at home and abroad that they could provoke a global trade war.

"We are an ally, not a threat," European Commission Vice President Jyrki Katainen said.

China's metals industry issued the country's most explicit threat yet in the row, urging the government to retaliate by targeting U.S. coal - a sector that is central to Trump's political base and his election pledge to restore American industries and blue-collar jobs.

Trump signed an order for the 25 percent tariffs on steel imports and 10 percent for aluminium at the White House on Thursday to counter cheap imports, especially from China, which he described as "an assault on our country".