A coalition of 25 Democratic-led US states has filed a federal lawsuit against the Trump administration, seeking to invalidate the latest round of tariffs imposed on imports from 60 trading partners.
The states argue that the president exceeded his legal authority by using forced-labour concerns as the basis for such broad trade restrictions.
The legal action asks a federal court to block the measures and order a reversal of the duties.
The lawsuit introduces significant legal uncertainty into the US trade regime.
Markets have been pricing in the durability of these tariffs, which were rolled out under the guise of combating forced labour.
A successful injunction could disrupt supply chains that have already adjusted to the new cost structure, while a dismissal would reinforce the administration's expansive interpretation of trade powers.