Get a list of s3 buckets associated with amazon access key?

I have tried googling how I could retrieve a list of available s3 buckets associated with an Amazon Access Key, but either I am searching the wrong terms, or I haven't went through enough results.

I have an access key and secret key, but I do not know the bucket name(s) associated with either the account or IAM user.

How can I get a list of the bucket names available using Powershell and AWS Tools?

Thanks!