is iphone 16 sold in Vietnam identical to those sold in France?

I'm not sure we are qualified to give you a definitive answer. This is a user to user only forum, not Apple Support. I can tell you that Apple manufacturers and sells iPhone with regional differences. And iPhone warranty is not international. If you live in France, buy your phone in France. It's almost never a good idea to buy your iPhone in a country which is different from the one you live in and will use your iPhone.

The Apple Support article I linked below, shows iPhone models, frequencies and carrier support. The article can be confusing to navigate. If you need additional assistance please let us know.

iPhone - Supported 5G and LTE networks - Apple

jean-marc211 wrote:

Regarding the warranty, we have asked Apple who said that provided that the phone is bought at an official Apple reseller, the warranty works once back in France.

I wouldn't take that as fact. Daily, we see people who believed that, but were denied warranty support on an iPhone purchased in a country other than the one they live (except all EU Countries are considered the same for Apple Warranty). It's your money, do as you please. Just don't come complaining if something goes wrong and you don't get the warranty support you thought you'd get.

Apple's published Legal Warranty document for iPhone says the following: "Warranty support may be limited to the country of purchase." That's NOT me saying that. That's Apple saying that. Again, your money. Do as you please.

jean-marc211 wrote:

Regarding the warranty, we have asked Apple who said that provided that the phone is bought at an official Apple reseller, the warranty works once back in France.

Take that with a grain of salt.

In theory, it is possible that you will be able to get warranty service outside of the country of original sale. That is not guaranteed.

In many cases, you can't even get paid service outside of the country of original sale.

Here is a link to the Apple’s worldwide warranty.

https://store.apple.com/Catalog/Images/worldwidewarranty.html

Independent Apple Authorized Service Providers may limit their warranty service. You may be required to ship the device. There may be delays due to shipping and parts availability. The warranty does not cover or address loaner devices. So, immediate replacement may be limited or unavailable.

Yes, they support all of them.

(259819)