Cloud Build is global. To run regional builds, use Cloud Build private pools. You can create private pools in a specific region and it will be managed by Google to be redundantly available across all the zones within that region. Regional support is available only for private pools; it is not available for default worker pools.
When selecting a region for your builds in private pools, your primary considerations should be latency and availability. You can generally select the region closest to your Cloud Build's users, but you should also consider the location of the other Google Cloud products and services that your build might integrate with. Using services across multiple locations can affect your app's latency, as well as pricing.
Cloud Build private pool is available in the following regions:
Once you create a private pool within a region, you cannot move it to another region.
Selecting the region
To select a region for your private pool, specify the region when creating the private pool. For instructions, see Creating a private pool.