Air Force planes flew over Washington on Tuesday after reports of an unidentified aircraft in restricted airspace, prompting a temporary closure of the White House.
The North American Space Defense Command said in a statement that its fighters "are in place."
She said the plane, believed to have violated US airspace, "is not currently considered aggressive."
Strict restrictions were imposed in Washington´s atmosphere after the attacks of 11 September 2001 in New York and Washington.
