Democrats will give President Donald Trump one last chance to leave office days before his term expires or face an unprecedented second impeachment over his supporters' deadly January 6 assault on the US Capitol.
The Democratic-led House of Representatives plans to vote as soon as Wednesday on formal charges of misconduct, known as articles of impeachment, unless Trump resigns or Vice President Mike Pence moves to oust him under a provision in the US Constitution.
The House is due to vote on Tuesday on a resolution calling on Pence, a Republican, to invoke within a day the 25th Amendment, a never-before used law that allows a majority of the Cabinet to strip the president of power if he or she is unable to discharge the office's duties.
Pence advisers say he is opposed to the idea.
The violence at the Capitol caused a serious rift between Trump and Pence, and the two men did not speak for days, although they did meet at the White House on Monday. A senior administration official said they discussed the riot.
"The two had a good conversation, discussing the week ahead and reflecting on the last four years of the administration's work and accomplishments," the official added.
If Trump has not stepped down and Pence has not taken action by Wednesday, Democratic leaders said they will bring his impeachment to the House floor, one week after the riot that forced lawmakers into hiding for hours and left behind five dead, including a police officer.
Meanwhile, US Representative Tom Reed, a moderate Republican, wrote in a New York Times op-ed that he and House colleagues would introduce a censure resolution against Trump on Tuesday as an alternative to a "rushed, divisive" impeachment.
But House Speaker Nancy Pelosi, the top congressional Democrat, told Democratic members on a conference call on Monday that a censure "would be an abdication of our responsibility," according to a source familiar with the call.
Democratic lawmakers introduced one article of impeachment on Monday, accusing Trump of inciting a violent insurrection with a fiery speech exhorting thousands of followers to march to the famous domed building where Congress was working to certify President-elect Joe Biden's election victory.
"The president's threat to America is urgent, and so too will be our action," said Pelosi.
With only eight days left in Trump's term, chances the Democratic drive will result in his removal appear remote.
Impeachment triggers a trial in the Republican-controlled Senate, which is in recess and not scheduled to return to Washington until January 19, the day before Biden is to be sworn in.
A Senate conviction requires a two-thirds vote, which means at least 17 Republicans would have to break with a president who has maintained an iron grip over his party for four years.
An impeachment trial could proceed even after Trump leaves office.
Trump's favourite means of communication was cut off last week when Twitter suspended his account permanently, saying it was concerned he could use it to incite further mayhem.
The president's actions have driven a wedge among Republicans, with a handful of lawmakers either calling for him to step down immediately or saying they will consider supporting impeachment.
After last week's chaos, authorities are hardening security ahead of Biden's inauguration, with as many as 15,000 National Guard troops authorised to deploy to Washington.
A federal law enforcement official told Reuters the FBI has warned that armed protests are planned for Washington and all 50 state capitals before January 20.
Australian Associated Press