Cross region read replicas

As mentioned on the AWS documentation:
MariaDB, MySQL PostgreSQL – https://aws.amazon.com/about-aws/whats-new/2017/01/amazon-rds-now-supports-read-replicas-of-encrypted-database-instances-across-regions/

Oracle – https://aws.amazon.com/about-aws/whats-new/2019/11/amazon-rds-for-oracle-now-supports-managed-disaster-recovery-and-data-proximity-with-cross-region-read-replicas/

Aurora SQL – https://aws.amazon.com/about-aws/whats-new/2016/06/amazon-aurora-now-supports-cross-region-replication/
Note that "Aurora PostgreSQL" does not currently support cross-region replicas – https://aws.amazon.com/rds/aurora/faqs/