Gillum posted a live video on Facebook on Saturday afternoon in which he congratulated DeSantis. Gillum had conceded to DeSantis on election night, but retracted it after the margin between the two candidates narrowed. The race went to a legally required recount, but after an initial machine recount DeSantis still led Gillum by more than 30,000 votes.
Gillum, who is Tallahassee's mayor, isn't saying what he plans to do next.
"Stay tuned," he said in his brief remarks. Nonetheless, Gillum says he will remain politically active, adding "the fight for Florida continues."
Gillum's announcement came hours after President Donald Trump said on Twitter that Gillum will be a "strong Democrat warrior" and a "force to reckon with."