WASHINGTON (AP) — Former Democratic presidential candidate Sen. Cory Booker of New Jersey has endorsed former Vice President Joe Biden. Booker announced on Twitter early Monday that Biden will “restore honor to the Oval Office and tackle our most pressing challenges.”

Booker ended his own presidential bid in January, pledging to do “everything in my power to elect the eventual Democratic nominee for president.”

“The answer to hatred & division is to reignite our spirit of common purpose,” Booker tweeted.

Booker planned to appear with Biden in Detroit and Flint, Michigan later Monday, according to a Biden aide.

His decision follows recent Biden endorsements by several failed Democratic presidential candidates, including Sen. Kamala Harris of California and former Massachusetts Gov. Deval Patrick. Former Biden rivals Amy Klobuchar, Pete Buttigieg, Beto O’Rourke, Mike

Bloomberg, Tim Ryan and John Delaney have also endorsed him.

Vermont Sen. Bernie Sanders has been endorsed by Marianne Williamson and Bill de Blasio.