Buttigieg dropping out of presidential race

Pete Buttigieg, the first openly gay US presidential candidate from a major party, on Sunday ended his campaign to be the Democratic nominee in the November election against Donald Trump, US media said.

The 38-year-old had risen rapidly from being a virtual unknown to becoming a national political figure, but he scored poorly in the latest primary in South Carolina, coming fourth with just eight per cent.

He was scheduled to address supporters later Sunday in South Bend, Indiana, where he was previously the mayor.

Buttigieg took centre stage when securing a narrow victory in the Iowa caucuses and earned national attention for his unflustered and professional approach in an often bitter Democratic nomination race.

But his showing in South Carolina on Saturday confirmed polls suggesting he struggled to attract support among black voters -- a key demographic.

Joe Biden's resounding victory in South Carolina has thrust him back into the race just days before voters go to the polls in 14 "Super Tuesday" states.

With 48 per cent of the vote in South Carolina, the former vice president more than doubled the 20 per cent won by national frontrunner Bernie Sanders, reviving Biden's campaign and positioning him as the leftist senator's main rival.

Trump responded rapidly on Twitter, claiming that the Democratic party leadership would act to halt Sanders winning.

"Pete Buttigieg is OUT. All of his SuperTuesday votes will go to Sleepy Joe Biden. Great timing. This is the REAL beginning of the Dems taking Bernie out of play," Trump wrote.