The U.S. Championships are later this month, with the world championships coming in October and the Olympics less than a year out.
Hidalgo previously said Russian competitors could take part under a neutral flag but she backpedaled on Tuesday in an interview with French media.
Attorneys have threatened civil and criminal action if the money is not returned within 10 days.
Police are punishing traders for cashing in by reselling scarce dolls of Olympics mascot Bing Dwen Dwen at up to 10 times retail price.
The Olympics will have strict guidelines to prevent the spread of the coronavirus.
Although Laurel Hubbard wasn't able to complete a lift for a chance to go for gold, she's been an Olympic pioneer for transgender athletes.
One of the Olympic Games' top sponsors announced it will be pulling any Games-related TV ads in Japan, citing "many issues with these Games that are proving difficult to be understood."
Fans were banned from the postponed Tokyo Olympics set to open in just two weeks after a state of emergency was declared on Thursday.
The U.S. State Department and CDC issued travel warnings this week urging Americans to avoid visiting Japan amid a surge in serious COVID-19 cases. In response, Japan said the travel warnings won’t have an impact on Olympians.
Japan has issued a third state of emergency for Tokyo and three western prefectures to curb a surge in the coronavirus just three months ahead of the Olympics.