Mr Key has said he favoured the design of a silver fern on a black background.
According to a Herald-DigiPoll earlier this week, a majority of New Zealanders did not believe it was time to change the national flag.
But if a new flag was chosen in a public referendum, the silver fern was by far the most popular design, the poll showed.
Asked if they felt the time had come for New Zealand to design a new flag for itself, 52.6 per cent of those surveyed said "No'' and 40.6 per cent said "Yes''.
The New York Times' article also pointed to a New Zealand Herald editorial, which urged Mr Key not to leave momentous aesthetic decisions in the hands of a committee of politicians, but to a panel of vexillologists, artists and designers.
"That makes sense. For practitioners of vexillology - the study of flags - an opportunity like this does not come often, and they are surely eager to make the most of it,'' the New York Times said