Will Supreme Court affirm Trump's monarchy?

Trading partners of the United States are facing a fresh period of uncertainty after a US federal appeals court ruled President Donald Trump's "reciprocal" tariffs were illegal.

- FELICITY DEANE

In a 7-4 majority, the judges ruled Trump had exceeded his power by invoking emergency powers to impose tariffs of "unlimited duration on nearly all goods from nearly every country in the world", upholding an earlier court decision.

The ruling will throw into disarray the strategies of trading partners still in negotiations with the US, who may decide to wait and see the outcome of the legal battle.

Although there are different options available to challenge the decision, Trump has made it clear the next stop will be the Supreme Court.

The US Court of Appeals for the Federal Circuit said the tariffs would remain in place until October 14, to allow time for further appeals.

The ruling tested the limits of executive power under the International Emergency Economic Powers Act (IEEPA) from 1977. Trump is the first president to use this act to impose tariffs, setting the stage for a test of executive power. At least for now, it is a test the administration appears to have failed. The judges rejected Trump's interpretation, which they said would place no limit on the president to raise revenue without any authorization from Congress.