Many US business associations have called on President Donald Trump to repeal the tariffs on steel and aluminum imposed last year.

The punitive tariffs not only meant higher costs for the importing companies - many industries also suffered from the counter-duties imposed by China, Mexico or the EU. The open letter addressed to Trump on Wednesday was signed by several dozen business associations.

"The continued implementation of steel tariffs is causing economic problems for US companies that depend on imported steel and aluminum," the letter says. For many "farmers, ranchers and industrial companies", the counter-toll damage is significantly higher than any benefit they would derive from the new free-trade agreement that Trump had agreed with neighboring Canada and Mexico.

In March 2018, Trump had increased imports of steel to the USA by 25 percent and of aluminum by 10 percent. Major trading partners such as China, Canada, Mexico and the EU also responded with high punitive tariffs on key US exports.

At the end of last year, the US agreed with Canada and Mexico on the new trade agreement USMCA. So far it is unclear whether the punitive tariffs on steel and aluminum will be eliminated.

The business associations urged Trump to clarify this question so that a "zero-inch trade" in the North American region could take hold again. They also offered their help for the deal to pass Congress.