I am trying to get started with the AWS CLI on OSX. I installed aws via pip. I have created a new user in IAM and attached the pre-built AdministratorAcce
aws
AdministratorAcce
In my case this was caused by not having the correct policy attached to the IAM user I was authenticating with.
Attach the AmazonEC2FullAccess policy to the user in the IAM Management Console and the command should work.
AmazonEC2FullAccess