The 67-second video on YouTube opens with a black slate that reads, "A Message to Japan." The video then shows a kneeling journalist, Kenji Goto, clad in an orange outfit.

Behind him, flaunting a knife, is the masked executioner from the Islamic State group whom the media has named "Jihadi John."

Addressing Prime Minister Shinzo Abe, "John" issues a harrowing threat: "Abe, because of your reckless decision to take part in an unwinnable war, this knife will not only slaughter Kenji, but will also carry on and cause carnage wherever your people are found. So let the nightmare for Japan begin."