WASHINGTON (Reuters) - U.S. President Donald Trump on Tuesday opened yet another front in his assault on global trade norms, ordering a new probe into possible new tariffs on copper imports to rebuild U.S. production of a metal critical to electric vehicles, military hardware, semiconductors and a wide range of consumer goods.

Mexican President has ramped up efforts to crack down on cheap imports from China, a move to appease Trump administration that’s threatening 25% tariffs on its North American trade partners.

President Donald Trump said Monday that his tariffs on Canada and Mexico are starting next month, ending a monthlong suspension on the planned import taxes that could potentially hurt economic growth and worsen inflation.