Singiser also worked on then-New York Sen. Hillary ClintonHillary Rodham ClintonDem rep: 'We must pause the entire Trump agenda' until Russia investigation complete New England Patriots to visit White House on April 19 More than ever, Justice must demand a special prosecutor for Trump-Russia probe MORE's presidential primary campaign, as the staff director for the Senate Democratic Steering and Outreach Committee, and in the Clinton White House.

Hillary Clinton now serves as secretary of State.

Singiser is the latest in a string of women at the White House to announce their departures. Melody Barnes, the president's domestic policy adviser, announced earlier this month plans to leave at the end of the year, while deputy communications director Jen Psaki, who had been with the president since his time as a senator in Illinois, said in September that she was joining a consulting group. Communications director Anita Dunn and energy and environmental adviser Carol Browner have also departed within the past year.