Joe Biden to announce 2020 presidential run next week: reports
Former US vice president Joe Biden arrives at a union rally in Dorchester, Massachusetts (AFP Photo/JOSEPH PREZIOSO)

Joe Biden will announce next week he is running for president, likely grabbing pole position in a crowded Democratic field eager to take on President Donald Trump in 2020, US media reported Friday.

Biden, the veteran politico who has sought the White House twice before and served as Barack Obama's vice president, will make it official with a video to be released Wednesday, according to several outlets.

NBC News and other American media reported that the long time Delaware senator's decision was all but a formality -- after he sat out 2016 as he mourned the death of his son Beau from cancer.

Biden, 76, will join the race as its predominant centrist at a time in which many in the Democratic Party's progressive wing, including rivals for the nomination, have embraced liberal policies like universal health care.

Several strategists see Biden as the down-to-earth Democrat with star power who connects with working class voters like those who abandoned Hillary Clinton for Trump in 2016.

In a Real Clear Politics poll released Tuesday, Biden led with 31 percent support among people asked about who they like in the Democratic primary elections, followed by self-declared democratic socialist Bernie Sanders at 23.

Some way behind, Kamala Harris of California, young Texas upstart Beto O'Rourke and rising star Pete Buttigieg were battling it out for third place -- with nine, eight and seven percent respectively.

Biden has been leading in other polls too in recent days.