If you are on your free tier period, you will find that it's easier to grant administrator policy to a single user, which will support access from all the Amazon command-line tools.
Here's what you need to do:
1. Go to your amazon console and navigate to IAM dashboard
2. Select policies from the menu on the left
3. Create Administrator Policy
4. select the Administrator checkbox and attach it your user
Now you will have full command line access for a specified user.