Maju Varghese, the Indian-origin director of the White House Military Office, has quit his post, citing personal reasons.
In a series of tweets on Saturday, Varghese said leading the White House Military Office (WHMO) was the honour of a lifetime.
"Overcome with lots of emotion today as a 2.5-year journey comes to a close. Grateful to have served POTUS and for the friendships that were forged in the tough days of the early primaries, when we were counted out but bounced back to win it all," wrote Varghese.
"Grateful to @BidenInaugural for giving the country a day to celebrate despite all the challenges we faced. Grateful to the men and women of the White House Military Office for taking me in and teaching me about service and sacrifice," he said.
An Obama administration alum, Varghese joined the Biden White House after leading the president's inauguration efforts and serving as a senior adviser and chief operating officer for Biden's 2020 presidential campaign, CNN reported on Friday.
Varghese "is departing his post Friday after several years working in President Joe Biden's orbit," it said.
The White House declined to say whether a replacement has been selected.
"One thing I learned during two tours here is it's a demanding place to work and it's because the work is really important, and we throw all of ourselves into this... Right now, it's best for me and my family that I kind of just try to strike a little bit more of a balance," Varghese, who is in his early forties, was quoted as saying to CNN.
He, however, did not detail his next endeavours.
As head of the military office, Varghese used to coordinate with the military branches responsible for supporting presidential operations at the White House and on the road domestically and abroad, including Air Force One missions, secure communications via the White House Communications Agency, food services, the medical unit and Camp David, the presidential retreat frequented often by the Biden family, the report said.
A lawyer by training, Varghese was born in the US to parents who immigrated from Tiruvalla, Kerala. He has a bachelor's degree in political science and economics from the University of Massachusetts, Amherts.
Among the chief challenges confronting Varghese over the past two years was crafting strategies for operating a campaign, inauguration and White House military support in the midst of the Covid-19 pandemic, the report said.
Deputy White House chief of staff Jen O'Malley Dillon called Varghese "one of the most tested, trusted and talented leaders on Team Biden".
"As the country faced confounding crises one year ago, he led the team that orchestrated a historic, unforgettable inauguration that defined the tone of our first year in office.
"Maju not only embodies the President's core values, but instils them in all of us through his service, optimism, and heart," Dillon was quoted as saying in the report.
In his tweets, Varghese thanked Dhillon and others for trusting him to lead teams "throughout this incredible ride".
"In the service of two Presidents and in the spirit of my father, I tried to lead with my whole heart. Thanks for everything, team! You'll always have me as a friend and ally," he said.
Varghese previously served in the White House under president Barack Obama in various roles, including as the assistant to the president for management and administration and deputy director of advance. He has also worked as the chief operating officer at The Hub Project and as a senior advisor at the law firm Dentons.