US Defence Department spokeswoman Ms Victoria Clarke has resigned her position as chief spin doctor to Secretary Donald Rumsfeld.
Praising Ms Clarke for developing innovative ways of presenting the US military to the public, Mr Rumsfeld said the Pentagon's spokeswoman had resigned from her job as of next Friday for personal reasons.
"Torie Clarke is a gifted communicator," Mr Rumsfeld said in a statement.
"During her remarkable two years of service in the Department of Defence, she has developed countless new methods to tell the story of our fighting forces and their courage, dedication and professionalism into sharp focus for all Americans. She will be sorely missed."
Ms Clarke is credited with the Pentagon's revolutionary agreement this year to allow hundreds of American and foreign journalists to travel with US and British invasion units into Iraq, a reporting process that became known as "embedding".
"I was convinced we needed widespread, direct coverage of the men and women in our military and to counter any attempts at disinformation by Iraq" she said.
Ms Clarke, a former public relations executive at the department knowing little about the military but was spokeswoman in the 1992 re-election campaign of former President George Bush. She says she is leaving her post to spend more time with her family.
She has had a close working relationship with Mr Rumsfeld as the US military fought wars in Afghanistan and Iraq.
"It breaks my heart to go and I'm going to miss it. It has been the greatest professional experience of my life ... it has been a true honour working for the men and women of the US military," Ms Clarke said.
She will be replaced on an interim basis by Mr Lawrence Di Rita, a special assistant to Mr Rumsfeld, until a permanent replacement is nominated by the White House and confirmed by the US Senate.
White House spokesman Mr Ari Fleischer, who also recently announced he would soon leave his post to return to private life, told reporters that Ms Clarke would be missed.
"She served our country very well at times of very serious military activity," he said. "The White House will miss her, I will miss her, the president will miss her."