An estimated security bill of $1m every day means Donald Trump is by far the most expensive US President-elect in history.
Taxpayers are paying out for what could grow to 300 New York police officers to protect the billionaire tycoon.
City officials say they will try for a reimbursement from the federal government but history suggests there is no promise they will recoup the funds.
“The complex challenges and tremendous costs associated with protecting a president and a president’s family in the heart of Manhattan are truly unprecedented,” said Austin Finan, the spokesman for New York mayor Bill de Blasio.
“As such, we will be issuing a full-throated request – with support from congressional leadership and our federal partners – for a complete reimbursement for all costs incurred.”
CNN Money reports, based on three city official sources, that protecting Donald Trump and his family costs $1m a day.
It also reports that the US Secret Service is considering renting a $1.5m-a-year floor, between 13,500 square feet and 15,500 square feet, in Trump Tower to protect the 70-year-old property magnet and his family.
Mr Finan said the $1m per day figure is not accurate, but City Hall has not provided its own estimate.
Wife Melania Trump also reportedly plans to stay living in the Fifth Avenue skyscraper, instead of moving into the White House in January, so 10-year-old son Barron can finish his school year uninterrupted.
An online Change.org petition, refusing to pay for the incumbent First Lady’s protection, has collected more than 105,000 signatures.
Barack Obama’s four trips to New York during the 2016 fiscal year cost $4.1m, including police overtime, according to the city’s Independent Budget Office - as reported in the New York Daily News.
The reports follow Mr Trump complaining about Chinese policy on Twitter and Klu Klux Klan members giving Nazi salutes at a parade dedicated to the President-elect.
The Independent has contacted the mayor's office and the Trump team for comment about the latest reports.
