John and Diane Foley, the parents of American photojournalist James Foley—who was executed by ISIS in a horrifying video released Tuesday—have released an email they received from the militants just a week before their son was killed.

The email, published in full on the Global Post, where Foley was a contributor, confirms that the group demanded a ransom for Foley's life:

You were given many chances to negotiate the release of your people via cash transactions as other governments have accepted,
We have also offered prisoner exchanges to free the Muslims currently in your detention like our sister Dr Afia Sidiqqi, however you proved very quickly to us that this is NOT what you are interested in.

The letter also issues a warning that America and its citizens "will pay the price" for its airstrikes in Iraq:

Now you return to bomb the Muslims of Iraq once again, this time resorting to Arial attacks and "proxy armies", all the while cowardly shying away from a face-to-face confrontation!

Today our swords are unsheathed towards you, GOVERNMENT AND CITIZENS ALIKE! AND WE WILL NOT STOP UNTILL WE QUENCH OUR THIRST FOR YOUR BLOOD.

James Foley's parents also appeared on the Today Show this morning.

"I actually was excited to see an email despite the conclusion that they would execute Jim,'' John Foley told Today's Tamron Hall. "We underestimated that point. I did not realize how brutal they were, and I actually hoped we could engage in negotiations with them if they were willing to send any sort of communication because we had none prior."

[Image via AP]