US President Donald Trump has warned that countries attempting to retreat from recent trade commitments could face steeper tariffs, following a Supreme Court ruling that struck down most of the broad import levies he imposed last year.
The warning came as governments worldwide reassessed tariffs and trade agreements after the court ruled last week that a 1977 emergency law did not authorize the sweeping measures.
In a post on Truth Social, Trump cautioned nations against using the decision to back away from deals negotiated in response to last year’s tariffs, saying any country that “plays games” with the ruling would face even higher duties.
The ruling has injected fresh uncertainty into global trade. On Monday, the European Union said it would suspend ratification of a trade deal agreed with Washington last summer, while India announced it would delay talks to finalize a recent agreement.
Officials said the decision has not altered the White House’s broader trade stance. Trump has already introduced a new global tariff of 15 percent under a different legal authority, set to take effect this week. The measure exempts some products and will expire after 150 days unless extended by Congress.
Countries that negotiated reduced tariffs in exchange for investment pledges or market access concessions are now seeking clarity. The UK said it was pressing US officials to confirm whether its agreement, which set tariffs at 10 percent, would remain valid.
UK Business and Trade Secretary Peter Kyle said the announcement had created uncertainty and that London was considering all options to protect businesses and consumers.
Bernd Lange, chair of the European Parliament’s trade committee, said approval of the EU-US deal had been paused while lawmakers sought clarity, describing the situation as “more uncertain than ever.”
Trump has turned to other legal tools to sustain his tariff agenda, including Section 122, which allows temporary tariffs without congressional approval, and Section 301 investigations into alleged unfair trade practices.
US Trade Representative Jamieson Greer said the administration had found ways to continue its policy despite the court setback, noting that while the legal mechanisms may change, the underlying approach would not.
Financial markets reacted nervously, with US stocks falling on Monday. Senate Democratic leader Chuck Schumer said Democrats would oppose any attempt to extend the new tariffs, arguing they would worsen economic harm.
Trump, however, insisted he does not need congressional approval to impose tariffs, signaling that trade tensions are likely to persist in the months ahead.
