AWS Security Token Service (STS) now supports enabling the global STS endpoint to issue session tokens compatible with all AWS Regions

AWS Security Token Service (STS) now enables you to request session tokens from the global STS endpoint that work in all AWS Regions. Using your AWS Identity and Access Management (IAM) users or roles, you can configure the global STS endpoint to vend session tokens that are compatible with all AWS Regions.  
Quelle: aws.amazon.com