Specify which AWS Regions your account can use

https://docs.aws.amazon.com/accounts/latest/reference/manage-acct-regions.html

aws account enable-region --region-name af-south-1
(no output)

aws account disable-region --region-name af-south-1
An error occurred (ConflictException) when calling the DisableRegion operation: Account 452850246549 and region af-south-1 is currently being enabled or disabled. Please wait until it finishes and then try again.

See also

• aws account [ enable-region | disable-region ]
• Amazon regions, Cross-region, Global View, aws account disable-region