It came as he launched a new $100 “Trump coin” to join his stock of merchandise and try tocatch up with Ms Harris’s fundraising boom.
Trump announced he would begin selling “incredible” new silver medallions, which are available to his supporters online.
The coins have been added to an increasingly bizarre collection of Trump merchandise, including gold trainers, cologne to commemorate the assassination attempt against him, digital trading cards that depict him as a superhero, and Taylor Swift spoof t-shirts.
The latest fundraising figures for his campaign, released on Saturday, show Kamala Harris raised four times more money than him in August.
In the first full month of her presidential campaign, Ms Harris raised almost $190m, compared with his $45 million. Her campaign war chest was valued at $235m at the end of the month, while his campaign had $134m.
Trump’s campaign sends daily texts to supporters, urging them to give to his campaign. His team has organised a lottery, the winners of which will be flown to Mar-a-Lago to meet the candidate himself.
Ms Harris has erased Trump’s fundraising advantage, which was built up in the months before Joe Biden left the presidential race on July 21. The figures show donors flocked to Ms Harris in the days after she announced she would run to replace him in the White House.
After the presidential debate on September 10, Ms Harris’s team said $47m was donated to her campaign, which was not included in the latest filings.
Trump is now unlikely to catch up with Ms Harris’s fundraising lead before election day on November 5.
The latest financial filings show a closer race between Trump’s main super PAC, MAGA Inc, and Ms Harris’s Future Forward. Trump’s body raised $25m in August, to Future Forward’s $37m. The Democratic National Committee also out-raised the Republican National Committee in the same period.