- It adds to the $155m cash on hand his campaign most recently declared.
- The event looks set to extend a growing cash gap between Mr Biden and his Republican challenger Donald Trump.
US President Joe Biden is about to host a record-breaking fundraiser in New York City, alongside his predecessors Barack Obama and Bill Clinton.
The event is projected to raise over $25m (£20m) for the Democrat's campaign - the most ever for a single political event, says his team.
It adds to the $155m cash on hand his campaign most recently declared.
The event looks set to extend a growing cash gap between Mr Biden and his Republican challenger Donald Trump.
Mr Trump is also in the New York area on Thursday, attending the wake of a police officer, Jonathan Diller, who was shot and killed in the line of duty.
Despite the Republican's lower fundraising and legal troubles, a number of national polls indicate he could still beat Mr Biden in their November rematch.
Over 5,000 people are expected to attend the star-studded Democratic fundraiser on Thursday night at Radio City Music Hall, with many more watching online.
Late-night talk show host Stephen Colbert will moderate a conversation with the three presidents.
The event will be hosted by actress Mindy Kaling and feature musical performances from Lizzo, Queen Latifah and Lea Michele.
First Lady Jill Biden will host an after-party for 500 guests. The president's son, Hunter Biden, and his family are also attending.
The tickets are priced between $225 and half a million dollars.
A photo with all three presidents will cost $100,000. Star photographer Annie Leibovitz is taking the snaps.
President Biden was joined on the Air Force One flight to New York by Mr Obama, whom he served as vice-president from 2009-2017.
Mr Obama, wearing a casual dress shirt, briefly came back for an off-the-record chat with reporters on the presidential jet.
New York ground to a halt for their arrival as the two men's huge motorcade cut across Manhattan in the pouring rain. Hundreds of onlookers jostled to take pictures.
Mr Biden's previous best single-day fundraising effort was the $10m he raised in 24 hours after his State of the Union address this month.
His fundraising has also been boosted by the advantage of incumbency.
"Biden raising a lot of money is probably a function of him not having any real primary challengers," Joseph Campbell, a communications professor at American University, told the BBC.
"There's no competition for Democratic donor money."
The $155m million in cash his campaign has is the most of any Democratic candidate in history at this point in an election cycle, according to his campaign.
Mr Trump and his political action committees reported having $74m.
The Republican candidate raised $20m in the whole of February, less than what President Biden expects to receive just from Thursday's event.
In addition to Mr Trump's fundraising challenges, his campaign and committees have spent millions of dollars in legal fees fighting four criminal cases against him.
Mr Trump, 77, blasted the Democratic fundraising event in a fundraising email of his own, sent out by his campaign on Thursday morning.
"Hundreds of deranged Hollywood liberals will be in attendance, and they will open their wallets to fund the destruction of country!" the message said.