Former US President and Republican presidential candidate Donald Trump arrives to speak at a campaign rally at the PPL Center in Allentown, Pennsylvania, on October 29, 2024. [AFP]

US President Joe Biden came under fire Tuesday for appearing to refer to Republican Donald Trump's supporters as "garbage" during an election campaign call.

Speaking in a video call with the nonprofit VotoLatino, Biden addressed the controversy that erupted after one of Trump's warm-up speakers at a New York rally on Sunday referred to Puerto Rico as a "floating island of garbage."

"The only garbage I see floating out there is his supporters," said Biden. "His, his, his demonization of Latinos is unconscionable and it's un-American."

In a statement, the White House said Biden was referring to Trump's rhetoric, not to his supporters.

"The President referred to the hateful rhetoric at the Madison Square Garden rally as 'garbage,'" said White House spokesperson Andrew Bates.

Biden's vice president, Kamala Harris, is locked in a too-close-to-call race against Trump for the White House, with Election Day just one week away.

The comments were seized upon by Trump's campaign, with the Republican presidential hopeful calling them "terrible."

"These people. Terrible, terrible -- terrible to say a thing like that," Trump said at a campaign rally in Pennsylvania.

He compared the comments to when Hillary Clinton -- running against Trump for the presidency in 2016 -- said half of the Republican's supporters were "deplorables."

"Garbage, I think is worse, right?" quipped Trump in Pennsylvania.

Trump's running mate J.D. Vance called Biden's words "disgusting."

"Kamala Harris and her boss Joe Biden are attacking half of the country," he said.

At the Trump rally in New York on Sunday, comedian Tony Hinchcliffe joked about Puerto Rico being a "floating island of garbage" and made further racist remarks about African Americans and Hispanic immigrants' sex lives.

Residents of Puerto Rico, an American island territory in the Caribbean, cannot take part in US elections, but the diaspora living in the United States numbers almost six million, according to Pew Research Center, and is eligible to vote.

On Tuesday, Trump continued his campaign's push to distance the former president from the comedian's comments.

"I don't know if it's a big deal or not, but I don't want anybody making nasty jokes or stupid jokes," he told broadcaster Fox News.

"Probably, he shouldn't have been there."