(Editor's note: This story has been updated with additional information.)
Eric Chewning, chief of staff to Defense Secretary Mark Esper, will be resigning at the end of the month and will be succeeded by Jen Stewart, currently the minority staff director for the House Armed Services Committee, according to a Pentagon statement.
Chewning joined DOD in October 2017 as the deputy assistant secretary of defense for industrial policy, where he oversaw a major defense industrial base review. He became the chief of staff to acting Defense Secretary Pat Shanahan in January 2019.
"I'm grateful for Eric's professionalism, judgment, and leadership over the last seven months as I moved into the secretary of defense role," Esper said in a statement. "In an incredibly demanding job, Eric has been a source of calm and tireless work. He will be missed by all. We wish him all the best upon his return to the private sector."
Stewart previously served as a senior adviser to former Chairman of the Joint Chiefs of Staff Gen. Joseph Dunford, and as the national security adviser to former House Speakers Paul Ryan (R-WI) and John Boehner (R-OH).
"I have known Jen for years and I'm excited to bring her into the department," Esper said. "Her deep expertise on national security issues will be a great addition to our team as we continue implementing the National Defense Strategy."
The House Armed Services Committee released a statement saying Stewart will be succeeded by Dan Sennott, currently a counselor and the Republican staff lead for the military personnel subcommittee. Sennott joined the committee in 2015 following 20 years in the Army.
Chewning is the latest in a string of senior leadership departures at DOD.
Pentagon Press Secretary Alyssa Farah said DOD "continues to bring in high quality personnel into leadership positions."
She noted that three new Senate-confirmed appointees will be sworn in this week, while three nominees await action in the Senate.
"And additional nominations are expected in coming weeks," she said. "Also this week, four new [senior executive service] SES appointees will be sworn in, joining approximately a dozen senior SES leaders brought into the Department in the last few months of 2019."