President Trump has ordered a tariff investigation into all US imports of key minerals

US President Donald Trump has ordered a tariff investigation into all US imports of key minerals, marking a major escalation in the global trade war.

Trump on Tuesday ordered an investigation into possible new tariffs on all US imports of key minerals, taking a swipe at industry leader China and further escalating his dispute with global trading partners.

Manufacturers, industry consultants and academics have long warned that the United States is overly dependent on China and other countries to supply the processed minerals that the entire American economy needs. Trump signed an executive order Tuesday at the White House directing Commerce Secretary Robert Lutnick to open a national security investigation under Section 232 of the Trade Expansion Act of 1962.

According to the executive order, the United States will explore market dynamics for all key minerals, including cobalt, nickel and 17 rare earth elements, to determine whether to impose tariffs. Uranium and other chemical elements deemed critical by U.S. federal officials were also included in Tuesday's tariff investigation.

Mr Trump used the Trade Expansion Act to impose 25 per cent tariffs on global steel and aluminium during his first term, and in February he used the same law to launch an investigation into potential copper tariffs.