Trump Threatens Countries That Would 'Play Games' With Tariffs

"Any Country that wants to 'play games' with the ridiculous supreme court decision, especially those that have 'Ripped Off' the U.S.A. for years, and even decades, will be met with a much higher Tariff, and worse, than that which they just recently agreed to," Trump wrote on social media.

The high court struck down Trump's global tariffs last Friday, ruling that he had exceeded his authority in tapping emergency economic powers to impose them.

This dealt a sharp blow to Trump's economic agenda, of which tariffs -- and his ability to impose them rapidly -- have been a key feature.

In a notice posted late Sunday, US Customs and Border Protection said it would stop collecting tariffs struck down by the court starting Tuesday.

But US Trade Representative Jamieson Greer maintained over the weekend that he expects partners to "stand by" the tariff deals they have struck with Washington.

After the Supreme Court ruled against Trump's country-specific tariffs last week, the US leader turned to a separate law to sign an order for broad 10-percent duties on imports, taking effect Tuesday.

He later vowed to hike this level to 15 percent.

Trump insisted in a separate Truth Social post Monday that "as President, I do not have to go back to Congress to get approval of tariffs."

He also claimed that the court gave him "far more powers and strength" with its ruling, and that he could use "licenses to do absolutely 'terrible' things to foreign countries."