Some 84 firefighters and medical crews responded as 26 emergency units with lights flashing converged on the crowded midtown Manhattan location, it added.
People posted video and images to social media, showing smoke rising from the building, which houses both residences and businesses.
Officials stressed there was no blaze within the building itself.
The Fire Department of NY says the fire started around 7 a.m. Monday at the building that contains U.S. President Donald Trump's home and business offices.
At least one firefighter suffered minor injuries after being hit by debris before being transported to the hospital.
Smoke from the fire could be seen coming from the roof of Trump Tower in New York City. There were no evacuations and no one was reported injured, the spokesman said. Trump was at the White House when the fire broke out.
The President in Washington D.C.at the time of the incident.