Can you deploy FTDv in AWS using Site-to-Site IPSEC tunnels wo/ NAT-T?

[red2play]

We have a customer who uses a basic VPN service and it doesn't support NAT-T.  Been trying for days to get it to work but it won't work.  We contacted the Vendor and they stated that they don't support NAT-T IPSEC tunnels.  IS there a way to deploy an AWS FTDv solution with a direct public IP or without NAT-T specifically?

[Pavan Gundu]

Do you see in the debugs that NAT-T is detected and it is trying to switch to port 4500?

[MHM Cisco World]

the NAT-T is oprtional not manadotry, 
so VPN S2S can work without any issue if both Peer use public IP. and not behind any NATing device.