Access ec2 instances across different regions using openvpn from one region

Hi Habeeb

Yes, this is possible using VPC peering. Peering your VPC in Singapore region to the relevant VPC in Oregon which will enable communications between them. Have a look at this -> https://docs.aws.amazon.com/vpc/latest/peering/what-is-vpc-peering.html

On a separate note AWS offers a service called AWS Client VPN which is a managed VPN service which will allow you to access AWS resources -> https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/what-is.html