Former President Obama reportedly told a 2020 Democratic presidential candidate that his former Vice President Joe Biden doesn't have what it takes to win the Oval Office.

Obama, 58, has remained relatively quiet during the first part of the Democratic primary; however, he has met with many of the candidates privately. In one particular meeting, the former president took a dig at his own vice president, according to Politico.

"With one candidate, he pointed out that during his own 2008 campaign, he had an intimate bond with the electorate, especially in Iowa, that he no longer has. Then he added, 'And you know who really doesn’t have it? Joe Biden,'" Ryan Lizza reported.

The former president's dig stands in stark contrast to the relationship Biden has depicted during his campaign. Biden, who has repeatedly stated that he doesn't want Obama's endorsement because whoever wins the primary "should win it on their own merits,” has frequently referenced his time working within the Obama White House.

The former vice president cites the Obama administration's record on healthcare as well as on the economy frequently. However, he has also been faced at times with difficult questions from his time in office. During multiple presidential debates this fall, Biden took heat from rival candidates for both relying on Obama's legacy when it suits him and for distancing himself from it when it was more beneficial for him.

There is a precedent for former presidents to hold out endorsing their second-in-command’s subsequent White House bids. Ronald Reagan did not endorse George H. W. Bush's candidacy in 1988 until it was clear who the GOP nominee would be. Then, there was the 1968 Democratic presidential campaign in which Lyndon B. Johnson declined to offer a robust endorsement of Hubert Humphrey until a little more than a month before the general election.

[Read more: ‘He knows absolutely nothing’: Obama hoped he would be a presidential resource for Trump]