The brutal video released on Saturday shows a British man, known as 'Jihadi John', who is believed to have carried out prior filmed executions for the Islamic State beheading Kenji Goto. The film is less than a minute long and shows Mr Goto kneeling down, in an orange jumpsuit, in front of the masked man armed with a knife.

The video is entitled "a Message to the Government of Japan" and the man addressed the Prime-Minister, Shinzo Abe, saying that "because of the 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".

Shortly after the release of the video, the Japanese Prime-Minister addressed the nation and condemned the "horrendous" killing, proclaiming that "Japan will not be defeated by Terrorism". The cabinet ministers will meet, today, to agree on a response to what the government considers "a despicable act of terrorism". Mr Goto's mother, Junko Ishido, paid tribute to her son saying her "heart is broken" and promising to carry on "with Kenji's mission to save the children from war and poverty".

The British Prime-Minister, David Cameron, and US President Barack Obama condemned the attack and promised to help Japan bring the extremists to justice.

Mr Goto was captured, in October, when he travelled to Syria to try and help secure the release of Haruna Yukawa, the other Japanese hostage held by ISIS, who was reportedly beheaded last weekend.

On Tuesday, a video released by the Islamic State featuring the voice of Mr Goto saying he "didn't have a lot of time left" proposed a prisoner exchange with the government of Jordan. Mr Goto and Jordanian hostage, Mu'ah Kasasbeh, would be freed if al-Qaida extremist, Sajida al-Rishawi, was released "in the next 24 hours".

She is currently on death row in Jordan for her involvement in a terrorist attack that killed over 60 people in an Amman hotel. The Jordanian government promptly agreed to the prisoner swap but the negotiations, conducted with the help of local Iraqi tribal leaders, reached a deadlock after further assurances about the safety of the two hostages were requested by Jordan.

A spokesman for the Jordanian government claimed, today, that they are still ready to release al-Qaida terrorist, al-Rishawi, if Lt. Pilot Mu'ah Kasasbeh is released unharmed.