Washington DC - President Donald Trump on Saturday doubled down on the sweeping tariffs he unleashed on countries around the world, vowing his "economic revolution" will yield historic results for Americans.

"We have been the dumb and helpless 'whipping post,' but not any longer. We are bringing back jobs and businesses like never before," Trump wrote on his Truth Social platform.

"This is an economic revolution, and we will win," he added. "HANG TOUGH, it won't be easy, but the end result will be historic."

A 10% "baseline" tariff came into place just after midnight, hitting most US imports except goods from Mexico and Canada as Trump invoked emergency economic powers to address perceived problems with the country's trade deficits.

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The trade gaps, said the White House, were driven by an "absence of reciprocity" in relationships and other policies like "exorbitant value-added taxes."

Come April 9, around 60 trading partners – including the European Union, Japan, and China – are set to face even higher rates tailored to each economy.

Already, Trump's sharp 34% tariff on Chinese goods, set to kick in next week, triggered Beijing's announcement of its own 34% tariff on US products from April 10.

Beijing also said it would sue the US at the World Trade Organization (WTO) and restrict the export of rare earth elements used in high-end medical and electronics technology.

"China has been hit much harder than the USA, not even close," Trump said in his post. "They, and many other nations, have treated us unsustainably badly."