Tech billionaire Michael Dell and his wife, Susan, have announced plans to donate $250 to 25 million children across the US.

The $6.25bn (£4.72bn) gift will bolster Trump-branded investment accounts, which were authorised by Congress as part of its tax and spending bill earlier this year with the aim of encouraging families save for retirement.

As part of that scheme, babies born between 2025 and 2028 are also eligible to receive $1,000 from the government.

The Dells said their gift, which targets children age 10 and under, was intended to help seed those accounts and expand the savings opportunity to even more children.

“We’ve seen what happens when a child gets even a small financial headstart – their world expands,” Michael Dell said in a video on social media announcing the donation.

Unlike the government plan, the Dells said children age 10 and under, who were born before 1 January 2025 were eligible for their gift, provided they live in areas where the median income is below $150,000.

The Dells said they expected the gift to reach almost 80% of children age 10 and under in the US. It is among the largest ever private donations to go directly to Americans.

Dell, the chief executive of Dell Technologies with a fortune that Forbes estimates at almost $150bn, also urged other philanthropists and employers to make similar commitments.

“Two great people. I love Dell!!!” President Donald Trump wrote in all capital letters on social media in response to the announcement.

The money will be routed through the new Trump-branded accounts, which by law must be invested in an index fund that reflects the wider stock market.

It is not currently possible to set up a Trump account. The government has said that process will launch next year, with more details available at that time.

Parents are eligible to contribute up to $5,000 in after-tax funds to the accounts, a figure that will be adjusted for inflation, with employers, charitable organisations and others also able to donate.

The child can access the money at age 18 at which point the account converts into a retirement account. While the money grows tax free, withdrawals are subject to taxes and possibly a penalty if made before the age of 59 and a half.

The White House Council of Economic Advisers earlier this year estimated that $1,000 could grow to more than $5,800 over the course of 18 years, assuming a 10.3% rate of return.

When they were created earlier this year, the Trump accounts met with significant scepticism from critics, who argued that the accounts would primarily benefit better off families, who have extra money to set aside, while being less flexible than other, existing savings vehicles.

The Tax Foundation, a think tank focused on tax policy, on Tuesday said that Trump accounts were “well intentioned” but would “add another layer to an already overcomplicated savings account system in the United States”.

“Trump Accounts do not offer much of an additional incentive to save,” it added. “Rather, the main benefit is in the form of the $1,000 initial deposit from the federal government and whatever employers choose to contribute.”

Treasury Secretary Scott Bessent also drew criticism from Democrats after promoting the scheme as a way to support alternatives to government-funded retirement benefits, calling it a “backdoor to privatizing Social Security”.