It serves as the headquarters for the Trump Organization and is located on Fifth Avenue between 56th and 57th Streets.
The city's Fire Department said the blaze started at about 7am (noon GMT) on the roof of the 68-storey building, which contains U.S. president Donald Trump's home and business offices.
Two minor injuries are reported; a firefighter who was hit with falling debris and a civilian.
But smoke continued emanating from a rooftop heating and cooling unit of the 58-story building, fire officials said. Both sustained minor injuries, and the engineer refused aid.
The Republican president announced his candidacy in 2015 at Trump Tower, his home for more than 30 years. He is scheduled to appear at an event in Tennessee Monday afternoon.
Kmart to close 64 stores this spring, including one in Cabot
Correction: An earlier version of this story incorrectly reported that the 5900 Old Seward Highway location was also closing. The closing store list includes 64 Kmart locations and 39 Sears locations, according to a Business Insider report .
More than 100 firefighters have responded to a call from Trump Tower, where a blaze has broken out in the NY building.
As firefighters sprayed water on the flames, steam billowed from the roof due to the frigid weather.
Investigators are looking into a possible electric issue as the cause of the fire, Sakowich said.
Trump's son Eric Trump tweeted about "a small electrical fire in a cooling tower" on the roof of the building and praised the FDNY for arriving "within minutes and did an incredible job".