Four people have died - including one woman who was shot - during violent protests, after supporters of Donald Trump stormed the US Capitol building.
Politicians were to formally declare Joe Biden the winner of November's election, which Donald Trump still falsely claims is fraudulent.
Tear gas was fired as crowds clashed with officers - two pipe bombs were found outside the headquarters of the two main political parties.
In dramatic scenes that drew international condemnation - including Taoiseach Micheál Martin and Foreign Affairs Minister Simon Coveney - supporters of Mr Trump brought violence to the seat of America's democracy on Wednesday - prompting the US Capitol to be put into lockdown.
Shocking & deeply sad scenes in Washington DC - we must call this out for what it is: a deliberate assault on Democracy by a sitting President & his supporters, attempting to overturn a free & fair election! The world is watching!
We hope for restoration of calm. pic.twitter.com/1OdQYEB35K— Simon Coveney (@simoncoveney) January 6, 2021
Mr Trump chose to post a minute-long video posted to his Twitter account.
He did not explicitly condemn the scenes of violence, but urged those who had gathered at the US Capitol to disperse.
Twitter swiftly added a warning message to Mr Trump's video, which read: "This claim of election fraud is disputed, and this Tweet can't be replied to, Retweeted, or like due to a risk of violence."
Facebook and YouTube went further and removed Mr Trump's video completely.
We've assessed two policy violations against President Trump's Page which will result in a 24-hour feature block, meaning he will lose the ability to post on the platform during that time.
— Facebook Newsroom (@fbnewsroom) January 7, 2021
US Vice President Mike Pence has defied Donald Trump by condemning the protests.