Democrats are expected to introduce the article of impeachment against President Trump in the House of Representatives on Monday for his role in the Wednesday’s invasion of the US Capitol.
House Speaker Nancy Pelosi said she would move forward with impeachment if Mr Trump did not resign immediately.
The charge of “incitement of insurrection” is set to be introduced by House Democrats on Monday.
They accuse Mr Trump of encouraging a riot in Congress in which five people died.
President-elect Joe Biden said impeachment was for Congress to decide, but said he had thought “for a long time President Trump was not fit to hold the job”.
The White House dismissed the impeachment as a “politically motivated” move that would “only serve to further divide our great country”.
Meanwhile US President Donald Trump has been permanently suspended from Twitter “due to the risk of further incitement of violence”, the company says.
Twitter said the decision was made “after close review of recent Tweets from the @realDonaldTrump account”.
It comes amid a Big Tech purge of the online platforms used by Mr Trump and his supporters.
Also, the FBI is appealing to the public for help in bringing the assailants to justice after the siege on the US Capitol building.