The World Trade Organization (WTO) has found that tariffs on aluminum and steel imports to the US imposed by former president Donald Trump's administration violated global trade rules.
Levies of 25 percent on steel and ten percent on aluminum were enacted in 2018, with Mr Trump citing unfair competition and national security considerations. The tariffs were later upheld and supported by the administration of Joe Biden, despite hopes from the US' trading partners that a new presidency would see the country loosen its trade restrictions.
While the tariffs have already been eased for some trade partners - including the European Union, Japan and the UK - through a series of exemptions and quotas made by both the Trump and Biden administrations, other nations continue to pay the levies in full. Cases against the tariffs were brought to the WTO's dispute body by China, Norway, Switzerland and Turkey.
In particular, the WTO panel rejected the national security grounds that were used to enact the tariffs, stating that they had not come "at a time of war or other emergency".
The ruling means that if the US does not adjust its policies to bring it into compliance, countries affected by the duties would be allowed to impose their own retaliatory tariffs on imports from the US in order to make up for any losses.
In a statement, China urged Washington to respect the ruling and alter its policies "as soon as possible", while Norway said the case should help ensure that the global "rules-based, multilateral trading system is not undermined".
However, the US has dismissed the ruling and stated it has no intention of removing the tariffs.
In a statement, spokesperson for the Office of the US Trade Representative Adam Hodge said: "The United States strongly rejects the flawed interpretation and conclusions in the WTO panel reports."
He added the body had "no authority to second-guess the ability of a WTO member to respond to a wide range of threats to its security" and the decision highlights the need for fundamental reform of the WTO's dispute resolution system.