White House chief of staff Ron Klain, who has spent more than two years as President Joe Biden’s top aide, is preparing to leave his job in the coming weeks, multiple media outlets reported late Saturday.

Mr. Klain’s expected departure comes not long after the White House and Democrats had a better-than-expected showing in the November elections.

The personnel change is also a rarity for an administration that has had minimal turnover so far. Halfway through his term, no member of Mr. Biden’s Cabinet has stepped down.

The White House did not return calls or emails seeking comment on Mr. Klain’s expected exit. Spending the weekend in Rehoboth Beach, Delaware, Mr. Biden did not respond to shouted questions about when his chief of staff is expected to depart.

Mr Klain sent an email to White House staff on Friday, which was the second anniversary of Mr. Biden’s inauguration. “Although much work remains ahead, as we look back on these two years, I am awestruck at what this team has done and how you have done it,” he wrote in the email, obtained by The Associated Press.

Among those said to be on the shortlist to succeed Mr. Klain are Steve Ricchetti, counselor to the president; Labor Secretary Marty Walsh; former White House COVID-19 response coordinator Jeff Zients; Agriculture Secretary Tom Vilsack; and Anita Dunn, a White House senior adviser.

Ms. Dunn has publicly ruled out interest in the chief of staff job but would be the first woman in the post. She played a leading role in shaping Mr. Biden’s political and communications strategy, including the “ultra-MAGA” framing of Republicans that helped Democrats exceed expectations during the 2022 midterms.

Mr. Zients has returned to the White House since running the COVID-19 response team in a low-profile role to ensure the administration is appropriately staffed for the remainder of Mr. Biden’s first term. Mr. Ricchetti, a former lobbyist, followed after Mr. Klain and senior adviser Bruce Reed as Mr. Biden’s final vice presidential chief of staff.

Mr. Walsh, Boston’s mayor before joining the Cabinet, earned praise from Mr. Biden as recently as Friday for his job performance. Mr. Vilsack, a former Iowa governor, is in his second stint as agriculture secretary after serving in the role for the entirety of the Obama administration. He volunteered for Mr. Biden during Biden’s ill-fated 1988 presidential bid in Iowa.

Other potential successors mentioned in media reports Sunday include President Obama’s national security advisor, Tom Donilon, whose brother, Mike Donilon, is a senior advisor in the White House; the former head of Mr. Biden’s Office of Presidential Personnel, Cathy Russell, currently the executive director of UNICEF; and former New Orlean Mayor Mitch Landrieu, Mr. Biden’s Infrastructure Implementation Coordinator.

Now that Republicans have regained a majority in the House, the White House is preparing to shift to a more defensive posture. GOP lawmakers are planning multiple investigations into the Biden administration, examining everything from the chaotic withdrawal from Afghanistan to the crisis at the border. Republicans are also pledging to investigate the president’s son, Hunter Biden.

Mr. Klain’s departure also comes as the White House struggles to contain the fallout after classified documents dating from Mr. Biden’s time as vice president were discovered at his home in Wilmington, Delaware, and at his former institute in Washington.