$gcloud app regions list
REGION SUPPORTS STANDARD SUPPORTS FLEXIBLE
asia-east2 YES YES
asia-northeast1 YES YES
asia-northeast2 YES YES
asia-northeast3 YES YES
asia-south1 YES YES
australia-southeast1 YES YES
europe-west YES YES
europe-west2 YES YES
europe-west3 YES YES
europe-west6 YES YES
northamerica-northeast1 YES YES
southamerica-east1 YES YES
us-central YES YES
us-east1 YES YES
us-east4 YES YES
us-west2 YES YES
us-west3 YES YES
-Thanks
Vijay
Hello Vijay,
Taking a look at the Cloud Tasks overview [1] you will see that Cloud Tasks requires an App Engine app to be able to host the queues. If you take a look at the currently available regions for GAE [2], you will see that the region `us-west1` is not listed, therefore, you cannot host the Cloud Tasks queues in that specific region.
I've noticed that you have created the following PIT [3] for this same issue. I have created a Feature Request on your behalf [4] that you can use to get the latest information from the GAE team. Notice that Feature Requests have no ETA nor guarantee to be implemented.
[1] - https://cloud.google.com/tasks/docs/dual-overview
[2] - https://cloud.google.com/appengine/docs/locations
[3] - https://issuetracker.google.com/150801133
[4] - https://issuetracker.google.com/150847681