The New Zealand flag featured in an Isis propaganda film last year when it was cited as one of 60 nations in "The global coalition against the Islamic State".
Drs Anne Speckhard and Ahmet Yayla, from the ICSVE, say the video is disturbing.
"Fill your cars with gas ... the video instructs as it shows an Isis soldier readying to run civilians down. Realistic depictions of attacks are illustrated on the film: a suicide vest attack in New York City, a sniper attack in London, activating a German sleeper cell, and a driver of an SUV preparing to run over crowds in Australia. The film references using an explosive-laden truck attack," the ICSVE report says.
The video is subtitled in English and accompanied by chanting in German.
It comes as authorities revealed the driver of the truck was a 31-year-old Frenchman of Tunisian origin. His ID was found in the truck's cabin.
In speeches and in videos previously Isis have suggested using cars and trucks as weapons to kill as many people as possible.
Two years ago the Isis spokesman Mohammed al-Adani, in a speech, called for the killing of disbelievers, including in Australia, using any means whatsoever, such as "run him over with your car".
"If you can kill a disbelieving American or European - especially the spiteful and filthy French - or an Australian or a Canadian, or any of the other disbelievers waging ware (against us), including the citizens of the countries that entered into a coalition against the Islamic State, then rely upon Allah and kill them in any manner or way however it may be. Smash his head with a rock, or slaughter him with a knife or run him over with your car or throw him down from a high place or choke him or poison him," al-Adani said at the time.
His words were highlighted by Peter Neumann, the director of the International Centre for the Study of Radicalisation at Kings College in London.
Mr Neumann also pointed out that "dozens and dozens" of people from Nice have gone to Syria to join IS.
An Isis propaganda video in 2014, recorded in French, the call to kill people with cars was reiterated.
"If you are unable to come to Syria or Iraq then pledge allegiance in your place - pledge allegiance in France. Operate within France. There are weapons and cars available and targets read to hit ... kill them and spit in their faces and run over them with your cars."
Al-Qaeda too has called for the deadly practice in an edition of the group's Inspire magazine, describing pick-up trucks as the "ultimate mowing machine" to mow down the Kuffar.
"The idea is to use a pick-up truck as a mowing machine, not to mow grass but mow down the enemies of Allah," the magazine said.