Async post to Amazon's SQS

I'd like to send messages to Amazon's SQS in a "launch and forget" mode (it's OK for some messages to get lost).

Today, I use this sync code:

client.UploadValues(uri, "POST", data);

Since this is going to be heavily used, I want to change this to an async method.

Is there a way to do this (either using plain .net or AWS SDK)?