Donald Trump has approved broad tariffs on imports of solar cells and washing machines in the first in a series of anticipated moves aimed at cracking down on China and fulfilling his protectionist promises to US rust belt voters. 

Employing a rarely-used provision in US law designed to protect domestic manufacturers from “serious injury”, Mr Trump on Monday ordered tariffs of up to 50 per cent on imported washing machines for the next three years and of up to 30 per cent on solar cells for the next four years. 

Although the US has imposed anti-dumping and other narrow tariffs against products as part of a quasi-judicial process over the past year, the tariffs announced on Monday mark the first signed off directly by Mr Trump since he took office.