As Democrats ramp up their efforts to have the president removed before his term officially expires, there are fresh security concerns over Mr Biden's inauguration on January 20.
The US National Park Service announced it had closed the Washington Monument after learning of what it called "continuing threats" to disrupt the inauguration.
And the FBI has warned of possible armed, violent protests that are being planned in both DC and across all 50 states in the lead up to January 20.
The National Guard has been authorised to send an additional 15,000 troops to the capital in response, with at least 10,000 due to arrive by Sunday.