Best practices in peering Azure Kubernetes cluster with AWS REST API

Question

Hi Team,

I am proposing a solution where we want to use external services from a 3rd party company which provides it via the privileged REST API from AWS cloud.

We want to peer this REST API via potentially REST/ MTLS call to our Kubernetes Cluster in Azure.
In essence, we want the two to be able to communicate in a safe manner both ways.

One potential solution is a separate Vnet with an Application gateway in front of each cluster on our side in Azure. 3rd party company plans on enabling traffic via internet and would whitelist our public IP.

Understand without an architecture diagram and more insights this is purely guessing the solution but trying to keep it simple and collect community feedback on best practices/ previous peering experience from you.

Thank you.
Dom