The woman in charge of improving the image of the US around the world has announced she will resign.
Karen Hughes, the head of public diplomacy for the US state department, said she will return to Texas after quitting her post in mid-December.
Hughes, who was sworn in as undersecretary of state for public diplomacy in September 2005, had sought to combat negative opinions about the US following the March 2003 invasion of Iraq and its chaotic aftermath.
But opinion polls around the world have continued to show an increase in negative perceptions of America.
"Attitudes have grown much more negative in many parts of the world," said Richard Wike, senior researcher with the Pew Global Attitudes Project in Washington.
Public support for the United States has even declined among allies such as Germany and Britain.
Wike's said the strongest negative view of the US was in the Muslim world.
Hughes was known for her fast-talking, exuberant style - a characteristic that occasionally backfired, especially in the Middle East.
As public diplomacy chief, she set up rapid-response units to respond to negative articles and gave ambassadors and other senior officials the authority to speak out to change public views about the US.
Hughes said: "I feel that I have done what Secretary Rice and President Bush asked of me by transforming public diplomacy and making it a national security priority."
Hughes had been close to Bush since before he entered politics by running for governor of Texas in 1994.
Apart from controversial political adviser Karl Rove, who resigned earlier this year, she was perhaps his most trusted aide.
She still regularly lunches with the president after her trips abroad.
Condoleezza Rice, the secretary of state, said the former television reporter would remain as a consultant for the department.
Rice said: "She will obviously leave a very big hole and big shoes to fill. She will remain a valued adviser to me."
Rice is one of the few remaining members of Bush's original team and she has said she plans to stay on until the end of his term.
Hughes will return to her home in Austin, Texas, where her husband remained while she took on the state department job.
She ran communications for Bush's first presidential election campaign in 2000 and was a counsellor during his initial 18 months in office before quitting for the first time.
She helped handle communications for Bush's 2004 re-election run.