President Barack Obama offered money to Joe Biden when his son was terminally ill, the vice-president has said.
Mr.Biden's son later died from brain cancer but when he had lost the ability to speak, his father thought he might have to sell his home. "Whatever you need, I'll give you the money," the president told his deputy over lunch, Joe Biden told CNN. The vice-president also said Bernie Sanders was more "authentic" on inequality issues than Hillary Clinton.
The Vermont senator and the former US Secretary of State are leading the field in the Democratic race to succeed Mr Obama.
Backing from the popular vice-president would be a coup but like the president, Mr Biden refused to publicly support either candidate. He did, however, imply Mr Sanders had more credibility on the issue of wealth disparity.
Sanders speaks to "a yearning that is deep and real", said Mr Biden, but Mrs Clinton was new to it.
"Hillary's focus has been other things up to now [but] no one questions Bernie's authenticity on those issues."
When he and the president had lunch and discussed Beau Biden's declining health due to a stroke, Joe Biden revealed his concern about how his son, Delaware's attorney general, would support his family if he was unable to work.
The vice-president and his wife had discussed selling their home in Wilmington, Delaware, he told Mr Obama: "Jill and I will sell the house and be in good shape."
The president's response was to push back against that idea, said Mr Biden, adding that Mr Obama would be "mad" he was telling the story.
"He said 'I'll give you the money. Whatever you need, I'll give you the money. Don't [sell the house], Joe, promise me. Promise me.'"
Beau Biden died in May last year and Mr Obama gave a eulogy at his funeral.
Months later, his father revealed he would not run for president in 2016.
