REHOBOTH BEACH, De. (Reuters) -Ron Klain, President Joe Biden’s White House chief of staff, plans to leave his post in the coming weeks, sources familiar with the matter said on Saturday, a major changing of the guard.

Klain has informed Biden of his plans, the sources said, confirming a New York Times story that said the long-serving aide would likely depart after the president’s State of the Union address on Feb. 7.

Klain, 61, has a long history at the White House, having served as chief of staff to former Vice President Al Gore and to Biden when he was vice president under President Barack Obama.

His departure is coming as Biden prepares to declare his intention to seek a second four-year term in 2024, an announcement anticipated after the State of the Union address.

The Times cited a lengthy list of possible successors to Klain: Labor Secretary Marty Walsh; former Delaware Gov. Jack Markell; Biden senior adviser Anita Dunn, counselor to the president Steve Richetti, former pandemic coordinator Jeff Zients and domestic policy adviser Susan Rice, along with Agriculture Secretary Tom Vilsack.

The news broke as Biden spent the weekend at his Rehoboth Beach, Delaware, home.

The chief of staff position is one of the most important at the White House, the senior political appointee responsible for driving the president’s policy agenda and ensuring appropriate staff members are hired.

The job can have a high burnout rate as the long days pile up. Klain’s tenure has been fairly lengthy comparatively speaking. Biden’s predecessor, Republican Donald Trump, burned through four chiefs of staff in four years including his first, Reince Priebus, who lasted 192 days.

(Reporting by Nandita Bose in Rehoboth Beach and Steve Holland in WashingtonEditing by Nick Zieminski and David Gregorio)