U.S.' lame-duck President Donald Trump said on Friday that he will not attend President-elect Joe Biden's inauguration, breaking with long-standing U.S. tradition.

"To all of those who have asked, I will not be going to the Inauguration on January 20th," Trump said on Twitter.

The announcement marks Trump's latest break with tradition, but it is perhaps one of his most profound as outgoing presidents have consistently attended their successor's inauguration.