The meeting took place on Wednesday, several days after Biden's June 27 debate with Republican presidential candidate Donald Trump. The debate started at 9 pm.
Getting more sleep and working fewer hours was part of the plan that the 81-year-old incumbent president presented to a group of more than 20 Democratic state leaders to reassure them he could still beat Trump in the race for the country's top job, the New York Times reported.
Biden's performance at the debate rekindled talks among Democrats about replacing him as the presidential nominee. Biden is the oldest president in US history and has faced speculations about his physical condition and cognitive abilities.
Earlier, Biden conceded that he "screwed up" during last week's debate with Republican presidential candidate Donald Trump, in what was the first such event of the 2024 election cycle.
"I had a bad night. And the fact of the matter is that I screwed up. I made a mistake," Biden said in an interview with the Earl Ingram Show, which aired on Thursday.
The 81-year-old argued that the debate had shown only 90 minutes of him and called on the Americans to look at what he had done in the past 3.5 years. He also pledged to win the upcoming presidential election.
Biden debated Trump at a CNN-hosted event in Atlanta on June 27.
The US presidential election is slated for November 2024. The main contenders expected on the ballot are Biden and Trump, who have both won enough delegates' votes to be their parties' presumptive nominees. Trump and Biden are set to debate again on September 10.