US House Speaker Nancy Pelosi has stepped up the pressure on Vice-President Mike Pence to act to remove Donald Trump from office over his role in last week's storming of Congress.
Lawmakers are expected to bring up a resolution asking Mr Pence to invoke the 25th Amendment to declare the president unfit for office.
Mr Pence is said to oppose the idea.
If he refuses, Democrats will vote to impeach Mr Trump who had urged supporters to march on the Capitol.
The Republican president has been accused by Democrats and an increasing number of Republicans over the riot, following a rally in which Mr Trump repeated unsubstantiated allegations of vote fraud. Five people died in the attack, including a Capitol police officer.
Mr Trump has made no public statements since he was banned from several social media platforms - including Twitter - on Friday.
He is due to leave office on 20 January, when Democrat Joe Biden will be sworn is as president. Mr Trump has said he will not attend Mr Biden's swearing-in ceremony.
