WASHINGTON — President Joe Biden was very publicly trying to rein himself in. “Don’t get going, Joe. Slow up,” he advised himself during a speech where he was criticizing Republican Donald Trump.

That was Tuesday afternoon. But by evening, Biden didn’t take his own advice, and now his off-the-cuff remark on a Zoom campaign call has created a new headache for Democratic nominee Kamala Harris less than a week before Election Day.

It’s not the first time Biden has created problems by going off script. But the latest incident served as a particular distraction just as Harris was trying to deliver a high-profile “closing argument’ for her campaign emphasizing the need to unify the country after Trump’s divisiveness.

Shortly before Harris was about to speak Tuesday night to a massive rally crowd on a stretch of grass not far from the White House, Biden got on a call with a Hispanic advocacy group and commented on a comic’s recent insults at a Trump rally where he referred to Puerto Rico as a “floating island of garbage.”

Biden said: “The only garbage I see floating out there is his supporters.”

The president quickly sent out a social media post seeking to clarify his remarks about Trump. “His demonization of Latinos is unconscionable,” Biden said. “That’s all I meant to say.”

But his sharp words were quickly seized on by Republicans who said he was denigrating Trump supporters.

Biden, who withdrew from the presidential race in July following a disastrous debate performance and near mutiny within his own party, has been largely absent from the campaign trail since then. But he’s intent on maintaining his relevance and cementing his legacy, and he has stepped up his political activity in recent days even as many in his party appear to be keeping their distance from him.

Harris, for her part, has been trying to differentiate herself from her unpopular boss. And she has been actively courting Republican voters.

Biden’s remarks prompted Harris on Tuesday to say that she strongly disagreed “with any criticism of people based on who they vote for.”