Fran Townsend, the leading White House-based terrorism adviser who gave public updates on the extent of the threat to U.S. security, is stepping down after 4½ years.
President Bush said Townsend, "has ably guided the Homeland Security Council. She has played an integral role in the formation of the key strategies and policies my administration has used to combat terror and protect Americans."
Her departure continues an exodus of key Bush aides and confidants, with his two-term presidency in the final 15 months.
Top aide Karl Rove, along with press secretary Tony Snow and senior
presidential adviser Dan Bartlett, left earlier this year.
In his statement, the President did note that Townsend had served in the position for more than 4½ years.
Townsend, who at one point had figured in speculation as to who would head the then-new Department of Homeland Security, was a familiar face, often appearing to argue the administration's position on morning news and Sunday interview shows.
She had a high profile in the administration's recent response to the devastating wildfires in California, saying the White House reaction to the disaster was going "exactly the way it should be" and assuring Californians the federal response would be "better and faster" than its performance in the wake of Hurricane Katrina's strike against the Gulf Coast states in 2005.
No reason was cited for Townsend's departure, and there was no word on a successor.