US President Donald Trump has promised there "will be an orderly transition on January 20th" after Congress certified President-elect Joe Biden's victory and following a day of violence in which his supporters stormed Capitol Hill.

President Trump's incendiary rhetoric reached a breaking point on Wednesday when his supporters stormed Capitol in one of the most jarring scenes ever to unfold in a seat of American political power.
President Trump's incendiary rhetoric reached a breaking point on Wednesday when his supporters stormed Capitol in one of the most jarring scenes ever to unfold in a seat of American political power. (AFP)

President Donald Trump for the first time has acknowledged his defeat in the November 3 election and announced there would be an "orderly transition on January 20th" after Congress concluded the electoral vote count certifying President-elect Joe Biden's victory.

Trump's acknowledgment on Thursday came after a day of chaos and destruction on Capitol Hill as a mob of his supporters stormed the Capitol building and unleashed unprecedented scenes of mayhem as it tried to halt the peaceful transition of power. 

Members of Congress were forced into hiding, offices were ransacked, and the formal congressional tally halted for more than six hours.

READ MORE: Twitter, Facebook block Donald Trump's accounts from posting

"Even though I totally disagree with the outcome of the election, and the facts bear me out, nevertheless there will be an orderly transition on January 20th," Trump said in a statement posted to Twitter by his social media director. 

His own account had been locked by the company for posting messages that appeared to justify the assault on the seat of the nation’s democracy.

"I have always said we would continue our fight to ensure that only legal votes were counted. While this represents the end of the greatest first term in presidential history, it's only the beginning of our fight to Make America Great Again."

Chaos in Capitol Hill

Trump has spent the last two months refusing to concede the election and making allegations of mass voter fraud that have been rejected by dozens of courts and Republican officials, including his former attorney general.

Vice President Mike Pence presided over the formal session in Congress that ended early on Thursday morning tallying the electoral college vote.

Trump's refusal to accept reality and his incendiary rhetoric reached a breaking point on Wednesday when his supporters violently occupied the Capitol in one of the most jarring scenes ever to unfold in a seat of American political power. 

Authorities said four people died during the violence, including one woman who was shot by an officer outside the House chamber.

READ MORE: Shocking, disgraceful and worrying: World reacts to US Capitol Hill riots

'Remember this day forever'

Trump had encouraged his supporters to march on the Capitol to protest lawmakers' actions and later appeared to excuse the violent occupation by the mob, which forced its way inside and clashed with police.

"These are the things and events that happen when a sacred landslide election victory is so unceremoniously and viciously stripped away from great patriots who have been badly & unfairly treated for so long," Trump wrote in a message that was later deleted by Twitter. 

He added, "Go home with love & in peace. Remember this day forever!"

READ MORE: US Congress certifies President-elect Joe Biden’s victory against Trump

Source: AP