Islamic State militants say they will execute a Jordanian pilot "immediately" if Amman does not hand over a female suicide bomber by sunset Thursday, as Japan waits in anguish for news of a journalist the extremists are also holding.
In a new audio recording, a voice identifying itself as Japanese freelancer Kenji Goto says his captors will kill Maaz al-Kassasbeh if an Iraqi woman on death row in Jordan is not handed over by the end of the day.
"If Sajida al-Rishawi is not ready for exchange for my life at the Turkish border by Thursday sunset, 29th of January, Mosul time, the Jordanian pilot Maaz al-Kassasbeh will be killed immediately," Goto said, in an unverified audio message distributed by IS-linked Twitter accounts.
It was not clear from the message if either Goto or Kassasbeh would be freed.
The recording was reported by monitoring group SITE Intelligence.
Japan's Chief Cabinet Secretary Yoshihide Suga told journalists the recording seemed genuine.
"We are in the process of confirming it, but it is highly probable that the voice is Mr. Goto's," he said.
The apparent communication breaks an anxious silence from the extremists since their previous 24-hour deadline for Rishawi expired at around 1400 GMT Wednesday.
Amman had offered to free the Iraqi woman, who was convicted for her part in triple-hotel bombings in the Jordanian capital in 2005 that killed 60 people, if the IS group released their airman.
"Jordan is ready to release the prisoner Sajida al-Rishawi if the Jordanian pilot is freed unharmed," state television quoted a government spokesman as saying Wednesday.
"From the start, the position of Jordan was to ensure the safety of our son, the pilot Maaz al-Kassasbeh," it added.
The government spokesman made no mention of Japanese hostage Goto.
Jordanian Foreign Minister Nasser Judeh wrote on Twitter shortly before 1500 GMT that his country was still awaiting confirmation that the pilot was safe.
Wednesday passed in a maelstrom of conflicting reports on the fate of the three key players, complicated by linguistic and cultural misunderstandings, and by the high stakes on all sides.
The atmosphere was tense in Jordan, where the country's involvement in the US-led air raids against IS positions is contentious.
The downing on December 24 of Kassasbeh's F-16 fighter jet over northern Syria and his subsequent capture and humiliation by jihadists exacerbated the situation. This week the pilot's father begged the government to save his son "at any price".
Japan, which plays no military part in the fight against jihadists, was thrust onto the front line last week when a video appeared in which Goto and Haruna Yukawa, a self-described contractor, were seen kneeling in the desert.
A masked knife-wielding militant said Tokyo had 72 hours to pay a $200 million ransom if it wanted to spare their lives.
When that deadline expired, new pictures appeared to show Yukawa had been beheaded, and a voice identifying itself as Goto demanded the release of Rishawi.
That twist left Japan pleading with Jordan, whose trump card -- talismanic Al-Qaeda operative Rishawi -- in the battle to get back its own captured airman had now been compromised.
In their next communication, on Tuesday, the IS group demanded Rishawi be handed over in exchange for Goto within 24 hours or both he and Kassasbeh would be killed.
Japan, a large donor to Jordan, has appealed for Amman's help, aware that they hold the key to Goto's safety, but also knowing that intense domestic pressure means the Jordanians must prioritise Kassasbeh.
The Japanese public has rallied round Goto, a respected war reporter and humanitarian, and though they are largely supportive of Abe's handling of the crisis thus far, may take a dim view if he does not come home alive.
Goto's mother, Junko Ishido, was at Japan's parliament Wednesday in a failed bid to meet Abe. After being refused an appointment, she issued a plea for her son's life through assembled media.
"Prime Minister Shinzo Abe," Ishido said. "Please continue your utmost efforts in negotiating with the Jordanian government until the last minute. There is not much time left."