Much of the complex was cordoned off as police and FBI agents investigated the truck which was driven onto the sidewalk near the Capitol building and Library of Congress for possible explosives.
A man appearing to be the suspect took to Facebook Live to stream a series of threats and asking to speak to President Joe Biden.
The 49-year-old man identified as Floyd Ray Roseberry from North Carolina was however arrested and taken into custody
The US Capitol Police on its Twitter feed describe the incident as an active bomb threat investigation.
