US President Joe Biden warned that he was "not confident at all" of a peaceful handover of power to Kamala Harris if Donald Trump loses November`s election, in an extract of a CBS interview broadcast Wednesday.

Biden, 81, who dropped out of the White House race in July and was replaced by Vice President Harris as the Democratic presidential nominee, said Trump`s hints on the campaign trail about not accepting a defeat should be taken seriously.

"If Trump loses, I`m not confident at all," Biden told the US network in the interview, which was due to air fully on Sunday, when asked if he believed there would be a calm transfer in January 2025.

"He means what he says. We don`t take him seriously. He means it -- all the stuff about `if we lose there`ll be a bloodbath,`" added Biden.

While campaigning earlier this year, Biden regularly brought up the fact that Trump`s supporters stormed the US Capitol on January 6, 2021, after Biden beat him in the 2020 election.

Biden also frequently quoted Trump as saying there would be a "bloodbath" if he lost -- although the Republican said he was talking in the context of electric car imports from China.

Trump has, however, maintained his false claim that the 2020 election was stolen from him, and in the CBS interview Biden accused the former president of trying to install allies in key electoral positions in US states to manipulate counts if the same thing happened again.

"You can`t love your country only when you win," said Biden.

The ageing president has long framed Trump as a threat to US democracy.

Harris has sometimes echoed that theme, while focusing more on a positive vision in a campaign that has reenergized Democrats, brought in millions of dollars and helped her nose ahead of Trump in opinion polls. BSS/AFP