Earlier, an audio message purportedly from a Japanese journalist being held by Islamic State militants said a Jordanian pilot, also captured, would be killed unless a prisoner swap was made by sunset on Thursday.
The message appeared to postpone a previous deadline set on Tuesday in which the journalist, Kenji Goto, said he would be killed within 24 hours if the Iraqi was not freed.
The latest audio recording, which could not be verified by Channel 4 News, was posted on YouTube early on Thursday.
Japanese Chief Cabinet Secretary Yoshihide Suga told a news conference that chances were high it was Goto’s voice in the recording.
“I am Kenji Goto. This is a voice message I’ve been told to send to you. If Sajida al-Rishawi is not ready for exchange for my life at the Turkish border by Thursday sunset 29th of January Mosul (Iraq) time, the Jordanian pilot Muath al-Kasaesbeh will be killed immediately,” the voice in the recording says.
Jordan said yesterday it had received no assurance that al-Kasaesbeh was safe and that it would go ahead with a proposed prisoner swap only if he was freed.
The audio tape message implied that the Jordanian pilot would not be part of the exchange deal, indicating any swap would be between Goto – a veteran war reporter – and Iraqi would-be suicide bomber, Sajida al-Rishawi. Any swap that left out the pilot would not go down well with the public in Jordan, where officials have insisted he is their priority.
There was no immediate comment from Jordanian government officials, but a security official said the authorities were trying to verify the authenticity of the recording and were coordinating with their Japanese counterparts.
Al-Rishawi was sentenced to death in Jordan for her involvement in a 2005 attack on a hotel that killed 60 people.
The hostage crisis erupted after Japanese Prime Minister Shinzo Abe, while on a tour of the Middle East, announced $200m in non-military aid for countries contending with Islamic State, but his government has rejected any suggestion it acted rashly and stressed the assistance was humanitarian.
Another Japanese hostage, Haruna Yukawa, was reportedly killed by militants on Saturday.