Officials in Maryland and Washington DC are expected to sue Donald Trump for accepting payments from foreign governments via his business empire.
The lawsuit cites the US constitution’s emoluments clause, which says no federal official should receive a gift or a fee from a foreign government.
The legal action alleges “unprecedented constitutional violations” by the US president, the Washington Post reports.
It would be the first such lawsuit filed by government entities.
A non-governmental organisation, Citizens for Responsibility and Ethics in Washington, lodged a similar legal action in January.
At that time, Mr Trump told a reporter in the Oval Office the case was “totally without merit”. He has not yet commented on the latest move.
Another legal headache – Analysis by Anthony Zurcher, BBC News
The constitutional challenges to Donald Trump’s ongoing business ties as president just got some state-level muscle behind them.
While the lawsuit by the District of Columbia and Maryland isn’t the first attempt …