The president of Planned Parenthood, Dr. Leana Wen, was ousted Tuesday after just eight months on the job as the organization faced unprecedented challenges related to its role as the leading abortion provider in the U.S.

Wen, in a Twitter post, said she learned that Planned Parenthood's board "ended my employment at a secret meeting." She indicated the board wanted more emphasis on political advocacy, while she sought to prioritize Planned Parenthood's role as a provider of health care services ranging from birth control to cancer screenings.

"We were engaged in good faith negotiations about my departure based on philosophical differences over the direction and future of Planned Parenthood," Wen said. "I am stepping down sooner than I had hoped."

Her departure came as the Trump administration announced it would start enforcing new rules that ban taxpayer-funded family planning clinics referring women for abortions. Planned Parenthood, the largest recipient of those funds, says it will not abide by those rules.

Without elaboration, Planned Parenthood announced Wen's departure via a Twitter post, thanking her for her service and wishing her luck going forward.

It also announced that Alexis McGill Johnson, co-director of a research consortium called the Perception Institute, will serve as acting president of Planned Parenthood and its political wing, the Planned Parenthood Action Fund, while a search for new permanent leader is conducted.

Wen, a Chinese immigrant who fled her native country when she was a child, took over as Planned Parenthood's leader in November, succeeding Cecile Richards, who had been president since 2006. Wen had been Baltimore's health commissioner since 2015

Wen's tenure coincided with major challenges for the U.S. abortion-rights movement, in which Planned Parenthood has long played a major role. Emboldened by a strengthened conservative presence on the U.S. Supreme Court, several Republican-controlled state legislatures have enacted laws this year aimed at banning most abortions. None of the laws have taken effect, but backers hope they might eventually lead the high court to overturn the 1973 Roe v. Wade ruling that establish a nationwide right to abortion.

Meanwhile, the Trump administration has moved to withhold federal family planning funds from clinics, including Planned Parenthood's, that refer women for abortions.

With about 400 clinics, Planned Parenthood is the largest provider in the federal family planning program for low-income women, known as Title X. The program does not pay for abortions, but until now clinics had been able to refer women for the procedure. Planned Parenthood clinics have long been a target for religious and social conservatives because the clinics separately provide abortions.

Jacqueline Ayers, Planned Parenthood's top lobbyist, said its clinics will stop accepting federal money and tap emergency funding as they press Congress and the courts to reverse the administration's ban.

Title X serves about 4 million women annually through independent clinics. Taxpayers provide about $260 million a year in grants to clinics, but that money by law cannot be used to pay for abortions.

In a letter to her colleagues at Planned Parenthood, Wen said she had believed its primary mission was to be a health care organization, more so than an advocacy organization.

"With the landscape changing dramatically in the last several months and the right to safe, legal abortion care under attack like never before, I understand the shift in the Board's prioritization," Wen wrote.