Configure Sublime SFTP plugin to work with Amazon AWS

[nisargshah95]

I am using Sublime Text 2.0.2 on Linux Mint. I have the username, public IP and the private key file (.pem) for my Amazon AWS EC2 instance. I wish to configure Sublime SFTP plugin to try to connect to my EC2 instance. Here's my sftp-config.json contents -

{
    // The tab key will cycle through the settings when first created
    // Visit *wbond.net/sublime_packages/sftp/settings for help
    
    // sftp, ftp or ftps
    "type": "sftp",

    "save_before_upload": true,
    "upload_on_save": false,
    "sync_down_on_open": false,
    "sync_skip_deletes": false,
    "sync_same_age": true,
    "confirm_downloads": false,
    "confirm_sync": true,
    "confirm_overwrite_newer": false,
    
    "host": "<public IP here>", // [I]Inserted appropriate IP here[/I]
    "user": "ec2-user",
    //"password": "password", // the EC2 instance does not have a password by default
    //"port": "22",
    
    "remote_path": "/home/user/app/workspace/",
    "ignore_regexes": [
        "\\.sublime-(project|workspace)", "sftp-config(-alt\\d?)?\\.json",
        "sftp-settings\\.json", "/venv/", "\\.svn/", "\\.hg/", "\\.git/",
        "\\.bzr", "_darcs", "CVS", "\\.DS_Store", "Thumbs\\.db", "desktop\\.ini",
        "\\.ppk", "\\.pem", "\\.com"
    ],
    //"file_permissions": "664",
    //"dir_permissions": "775",
    
    //"extra_list_connections": 0,

    "connect_timeout": 30,
    //"keepalive": 120,
    //"ftp_passive_mode": true,
    //"ftp_obey_passive_host": false,
    "ssh_key_file": "/home/user/app/workspace/AppName.pem",
    //"sftp_flags": ["-F", "/path/to/ssh_config"],
    
    //"preserve_modification_times": false,
    //"remote_time_offset_in_hours": 0,
    //"remote_encoding": "utf-8",
    //"remote_locale": "C",
    //"allow_config_upload": false,
}

Sublime Text console gives the following error when I try to connect -

Connecting to SFTP server "[I]public IP here[/I]" as "ec2-user" .. failure (Connection refused)

Any suggestions on where I am going wrong? (I do not wish to disclose the public IP of my EC2 instance and hence have replaced it with text)