There was no confirmation that there was any device in the vehicle but security at the White House was immediately upgraded. One person was in custody after the incident and the vehicle was being checked, the officials added.
Several streets around the White House were closed. It was the second scare at the White House on Saturday after a person earlier jumped over a bike rack in a buffer zone in front of the White House.
US President Donald Trump was in Florida at the time of both incidents.
In the first incident, the unidentified person was not able to make it over the fence into the grounds, White House spokesman Sean Spicer said on Twitter.