He spoke about this in an interview with the Prime agency.
In particular, Tkachenko specified that the messenger will no longer be supported on models with iOS 10 or 11.
The expert advised to update the system to 12 in order for the application to work.
In addition, Tkachenko warned, the messenger will completely stop working on iPhone 5 and iPhone 5C models.
Earlier, the founder of Telegram, Pavel Durov, said that hackers can access the phone due to security problems with the WhatsApp messenger.