Former President Barack Obama has told Joe Biden that his top advisers are too old and out of touch with the political climate, according to a new report on their relationship.

Biden enjoys frontrunner status in the 2020 Democratic primary in large thanks to being Obama's vice-president. He has robust support among African American voters and strong popularity in the party.

The New York Times reported Obama hasn't backed off a pledge to not endorse anyone before the nomination is decided, but he's still in close contact with Biden and urged him to reach out to younger assistants:

In his interactions with Mr. Biden — the pair had a quiet lunch in Washington last month — Mr. Obama has hammered away at the need for his campaign to expand his aging inner circle. He has communicated his frustration that Mr. Biden’s closest advisers are too old and out of touch with the current political climate — urging him to include more younger aides, according to three Democrats with direct knowledge of the discussion.

The Times reported Obama also summoned Biden campaign officials Anita Dunn and Kate Bedingfield to his office in March. He said they needed to ensure, whether Biden won or lost, he didn't embarrass himself or "damage his legacy."

While Biden has maintained a polling advantage since entering the race in April, he has Sens. Elizabeth Warren (D., Mass.) and Bernie Sanders (I., Vt.) nipping at his heels.

Known for his loose tongue, Biden has committed a series of gaffes that tripped up his momentum, and he performed poorly at the first Democratic debate. It's his third bid at the presidency, following a disastrous failed bid for the 1988 nomination and a short-lived one in 2008.