Clone a mongodb collection from ec2 - couldn't connect to server

I am attempting to copy a collection from a database on a live ec2 server to my local machine using the following command:

db.cloneCollection("xx.x.xx.xxx", "collectionName", {})

I'm getting the error message "couldn't connect to server xx.x.xx.xxx:27017 (xx.x.xx.xxx), connection attempt failed"

Both databases have the same name.

I am able to connect to the database on ec2 using an ssh key on Robomongo - do I need to add anything to the command to support ssh?