The US Democratic Party has begun a formal impeachment inquiry into President Donald Trump over allegations that he pressured a foreign power to damage a political rival.
Top Democrat Nancy Pelosi said the president “must be held accountable”.
Mr Trump has denied wrongdoing and called the efforts a “witch hunt”.
There is strong support from House Democrats for impeachment, but the proceedings would be unlikely to pass the Republican-controlled Senate.
The high-stakes move by House Speaker Ms Pelosi, prompted by allegations that Mr Trump pressured the Ukrainian president to investigate his leading political rival Joe Biden, lays the groundwork for a potentially hugely consequential confrontation between Democrats and the president ahead of the 2020 election.
If the inquiry moves forward the House of Representatives will vote on any charges and, with the Democrats in the majority, the vote would likely be carried – making Mr Trump the third president in US history to have been impeached.
But the proceedings would likely then stall in the Senate, where the president’s Republican Party holds enough seats to prevent him from being removed from office by a two-thirds majority.
Ms Pelosi did not provide any timeline for how the process might play out.