U.S. President Joe Biden will hold a number of fundraisers with wealthy Democratic donors in coming weeks as part of his expected bid to return to the White House in 2024, according to three sources familiar with the plans.

Biden and the Democratic National Committee will host fundraisers in New York and Philadelphia next week that coincide with official presidential visits touting legislative successes. Then, the pace and volume of the fundraisers are expected to accelerate in March, the three sources said.

"We have been told to expect fundraising to ramp up in the March and April time frame," said one donor who helped Biden raise money in 2020 and is committed to doing the same this time around.

Biden has yet to officially say he is running for re-election, but he is expected to announce his bid in the weeks after the State of the Union speech scheduled for Feb. 7.

The fundraising kickoff will focus on high-dollar donors as the campaign seeks to raise a war chest of a better part of a billion dollars, for what is expected to be the most expensive presidential campaign in history.

Biden's campaign in 2020 was the first presidential candidate in history to raise over $1 billion, as he battled Republican Donald Trump.

The Democratic National Committee will also need to raise money to help defend a tough congressional map in 2024 that includes defending Senate seats in Ohio, West Virginia, Arizona and Montana.

Outside groups raised another $580 million for Biden in 2020. Aides are divided over whether to rely on a super-PAC this time around for outside help, and, if so, which one, sources tell Reuters.

Biden will need to turn to the same Wall Street and tech industry donors his administration has sometimes demonized and who have at times felt ignored and passed over for international ambassadorships.

The New York City fundraiser on Tuesday will be hosted by Jeffrey Weber, a wealthy, former hedge fund executive, according to an invitation seen by Reuters.

The upcoming fundraising effort represents an early test of enthusiasm for a Biden re-election effort, and an early endurance test for an 80-year-old president who will have to balance the rigors of the White House with that of the campaign trail.

In 2020, the COVID pandemic forced Biden to stay off the campaign trail and raise money through virtual fundraisers. This time around, Biden will be forced to run a more traditional campaign that includes a mix of official presidential duties, campaign stops and fundraising events.