https://wccftech.com/pixel-4s-motion-sense-will-work-in-these-countries/

Despite the Google Pixel 4 not technically being released yet, we have tons of information about some of its new features. One of the more interesting features of the lot is what Google calls  Motion Sense. It uses radar technology to track hand gestures. Motion Sense is powered by Google’s Project Soli, which uses advanced radar technology. Soli sensor technology works by emitting electromagnetic waves in a broad beam. Objects within the beam scatter this energy, reflecting some portion towards the radar antenna. Properties of the reflected signal, such as energy, time delay, and frequency shift capture information about the object’s characteristics. Based on the responses generated by different gestures, the signal sent back can be programmed to perform a host of pre-determined tasks.

Due to the sensitive nature of the technology involved, Google needs to get a host of permissions for Project Soli to be able to work in many countries. There is also a high likelihood of Motion Sense not being available in several regions due to regulatory restrictions in the country. 9to5Google did some digging and managed to unearth the full list of countries where Motion Sense will work for sure. Here they are: