Speaking at a press briefing on Monday, Adams said casualties from the fire included nine adults and eight children, reports Xinhua news agency.
New York City Fire Commissioner Daniel Nigro said there was a bit of double count and it's a bit of good news that the number of deaths isn't 19 but 17.
Nigro added that there are many people fighting for their lives in the hospitals and the death toll could increase again.
"We're certain that the fire started with a faulty portable electrical heater," said Nigro, noting investigation by fire marshals is still under way.
Meanwhile, local government agencies and social organisations are working to provide support to victims of the fire as well as people evacuated from the apartment building known as Twin Parks North West.
New York Governor Kathy Hochul said on Sunday evening that efforts would be made to rebuild lives and give victims hope, "especially those who came all the way from Africa, Gambia, in search of a better life right here in this great borough, the borough of Bronx".
Hochul announced that a compensation fund would be established for the victims of the fire to help them find new housing, for burial costs and other costs.
The Mayor's Fund to Advance NYC, a non-profit organisation that facilitates innovative public-private partnerships, is raising money to support victims of the fire in partnership with Adams and the City of New York.
As of Monday noon, a GoFundMe fundraiser organised by the Gambian Youth Organization (GYO) had received over $400,000, more than double of its goal of $200,000.
The apartment building, built in the 1970s, is home to working-class families, many of whom depend on Section 8 rental assistance.
Adams said the building was home to many African immigrants who chose their homes for the close-knit community and short distance to local mosques.
A significant number of the building's residents were practicing Muslims and originally from Gambia, according to a report by the New York Times.
New York City would fly flags at half-staff until sunset on Wednesday as a mark of respect for the victims of the tragic fire, according to the Mayor's office.