Biden was asked about the possible candidacy of former New York Mayor Michael Bloomberg.
Bloomberg adviser Howard Wolfson says other candidates already have a big head start in the first four states to vote - Iowa, New Hampshire, Nevada and SC - and Bloomberg needs to be realistic about where he can make up ground.
The president added that he thought Bloomberg would hurt former Vice President Joe Biden's run in the Democratic primary.
The tycoon had strongly hinted that he would run, with his adviser Howard Wolfson releasing a statement on Thursday evening saying they wanted to "ensure that Trump is defeated" in the election next year.
Mr Bloombergs team also contacted Gina Raimondo, the governor of Rhode Island and the chairwoman of the Democratic Governors Association.
Bloomberg is estimated to have wealth worth about $52 billion and will plan on self-funding his presidential campaign, while the rest of the DNC primary field focuses on fundraising. "You skip the early states, you're going to have a hard time".
There is no filing requirement for a candidate to run in the Iowa caucuses, which are a series of Democratic Party meetings, not state-run elections.
Buckley and Price say they hope voters "will have that opportunity". One Democrat Bloomberg hasn't spoken to as he's reconsidered his run is former president Barack Obama. Late Thursday night, it was reported that Bloomberg was set to run for president as evidenced by an effort to beat the deadline to be on the Alabama ballot.
Trump was responding to news that the billionaire Blomberg is opening the door to a 2020 White House bid.
I used to think the answer was obviously the latter.
Still, his advisers acknowledge his late entry to the race could make competing in states like Iowa and New Hampshire, which have been blanketed by candidates for almost a year, difficult.
Billionaire former New York City Mayor Michael Bloomberg is opening the door to a 2020 presidential campaign. But I wonder now how much Donald Trump's success in 2016 really had to do with his being a billionaire, as opposed to someone who is very good at playing one on television.
Bloomberg has expressed concern about the Democratic Party's leftward slant, led by Sens.
It is believed that Mr Bloomberg bowed out of the 2020 race because of Mr Bidens apparent strength, but has become concerned that he is not on track to win the Democratic nomination.
There is considerable skepticism among the leading Democratic candidates about Bloomberg's path forward in a 2020 primary.