Former US vice president Joe Biden (right) and his old boss Barack Obama bonded over eight years in the White House and remain close (Brendan SMIALOWSKI)

Washington (AFP) – Former US vice president Joe Biden, who launched his White House bid Thursday, said he asked old boss Barack Obama not to endorse him because Democrats should try to win the nomination on their own merits.

Shortly after Biden’s announcement, a source familiar with Obama’s thinking said he was “unlikely” to endorse this early, noting that the 44th president believed the robust primary debate in the run-up to 2008 had shaped him into a better candidate.

“I asked president Obama not to endorse,” Biden told reporters in Wilmington, Delaware, adding: “Whoever wins this nomination should win it on its own merits.”

Biden is the latest of 20 candidates seeking the Democratic nomination, a field that includes senators Bernie Sanders, Elizabeth Warren and Kamala Harris, several current and former members of the House of Representatives and Obama’s former cabinet member Julian Castro.

Asked why he believed he is the party’s best choice to go up against President Donald Trump in 2020, Biden demurred: “That’ll be for the Democrats to decide.”

The Obama source said the former commander in chief was “excited” by the extraordinary and diverse talent in the Democratic lineup and believed it would be best “to let the candidates make their cases directly to the voters.”

Obama and Biden “forged a special bond” during their eight-year administration and remain close, according to Obama spokeswoman Katie Hill.

Days before the end of his presidency in January 2017, Obama surprised Biden by presenting him with the Presidential Medal of Freedom, the highest civilian honor in the United States.

Disclaimer: Validity of the above story is for 7 Days from original date of publishing. Source: AFP.