WASHINGTON (CNN) -- The mastermind of U.S. public diplomacy efforts in the wake of the terrorist attacks of September 11, 2001 resigned from her State Department post Monday.

Charlotte Beers, a former top advertising executive who joined the department shortly after September 11, is leaving shortly "for health reasons," Secretary of State Colin Powell said in a written statement.

Another U.S. official told CNN that her departure was connected to problems she encountered in the job.

Beers, 67, took office to spearhead a public diplomacy campaign aimed at winning the hearts and minds of the Arab and Muslim world. But she attracted little praise for her efforts, and was attacked in the media and by various think tanks and members of Congress.

Privately, U.S. officials also complained that though Beers spent a lot of money on slickly produced media ads, she did not understand her target audience: Arab and Muslim-majority countries where anti-American sentiment runs high.

"She was failing," the official said. "She didn't do anything that worked."

Beers, whose title was undersecretary of state for public diplomacy, acknowledged to a Senate committee Thursday that her task was daunting, The Associated Press reported.

"The gap between who we are and how we wish to be seen, and how we are in fact seen, is frighteningly wide," Beers told a Senate Foreign Relations Committee hearing.

Beers' "Shared Values" campaign -- television ads portraying Muslim-Americans in their daily life -- was criticized in the few countries it was introduced. The series was eventually suspended when several Arab countries refused to broadcast the ads.

"The administration waited until the fallout from the Shared Values campaign ended," the official said, citing several critical media reports about Beers. "But we have been looking for an honorable exit for her for some time."

The official said the White House, which has established its Office of Global Communications to distribute U.S. propaganda as the United States readies for a possible war with Iraq, "has been distancing itself from Charlotte since day one."

According to her State Department biography, Beers was the only person to serve as chairman of two of the top 10 worldwide advertising agencies: J. Walter Thompson and Ogilvy & Mather.

Beers' resignation will take effect in about two weeks. Patricia Harrison, assistant secretary of state for education and cultural affairs, will temporarily fill Beers' post, the official said.

Powell, in his written statement, said Beers "brought new energy, new ideas, and new enthusiasm to our interaction with the public in America and throughout the world. ... At a critical and stressful time for our nation, she and her team sharpened our policy advocacy and took our values and our ideas to mass audiences in countries which hadn't heard from us in a concerted way for years.