My iPhone Keeps Unpairing From my Apple Watch During Setup

I have an iPhone 7 and a Series 2 Apple Watch and I recently tried to pair them. I scanned the Apple Watch, and then it said that there was a new update, so I pressed don’t download it, and then it just said “Unpairing Apple Watch” and sent me back to the start. I have repeated this process but it hasn’t worked. Does anyone know how to solve this?