Washington (CNN) Anti-abortion activist Teresa Manning resigned from her post as deputy assistant secretary for population affairs on Friday, a Health and Human Services Department spokesman tells CNN.

"HHS would like to thank her for her service to this administration and the American people," the spokesman's statement read. It did not provide a reason for Manning's resignation.

Valerie Huber, an advocate for abstinence education, has been named acting deputy assistant secretary for population affairs, the spokeman said. Huber previously served as chief of staff for the assistant secretary for health at the department.

The Washington Post first reported Manning's resignation.

Because of her anti-abortion advocacy and public skepticism of birth control, Manning was a controversial choice to lead the HHS family planning division when she was appointed by President Donald Trump last May.