Islamic State in Iraq and the Levant (ISIL) released a message late Wednesday purportedly by Japanese hostage Kenji Goto, extending the deadline for Jordan's release of an Iraqi would-be hotel bomber linked to Al-Qaeda.
The audio was released as Jordan had offered a precedent-setting prisoner swap to ISIL in an attempt to save a Jordanian air force pilot the militants purportedly threatened to kill, along with Goto.
The audio recording, in English, said the Jordanians must present Sajida al-Rishawi at the Turkish border by sunset Thursday, or Jordanian pilot Moaz al-Kassasbeh will be killed.
"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 Moaz al-Kassasbeh will be killed immediately," Goto said, in an unverified audio message distributed by ISIL-linked Twitter accounts.
It was not clear from the message if either Goto or the pilot would be freed. The recording was reported by monitoring group SITE Intelligence.
In Tokyo on Thursday, Japanese government spokesman Yoshihide Suga said the government was analyzing the latest message. He said Japan was doing its utmost for the release of Goto, working with nations in the region, including Turkey, Jordan and Israel.
"We are trying to confirm [the message], but we think there is a high probability that this is Mr. Goto's voice," he said.
Suga refused comment on the specifics of the talks with Jordan, saying the situation was developing. Japan's cabinet was meeting to assess the latest developments.
Japan's Prime Minister Shinzo Abe reiterated his condemnation of the hostage taking. "This heinous terrorist act is totally unforgivable," he said.
Wednesday passed in a swirl of conflicting reports on the fate of the three key players.
During the day, pilot's father met with Jordan's king, who he said assured him that "everything will be fine."
King Abdullah II faces growing domestic pressure to bring the pilot home. However, meeting the ISIL demand for the release of a would-be hotel bomber linked to Al-Qaeda would run counter to the kingdom's hard-line approach to ISIL.
Over the weekend, an video emerged online showing a still photo of Goto. It included a recording of a voice claiming to be Goto, saying his captors wanted the release of Rishawi, an Iraqi woman sentenced to death in Jordan for involvement in a suicide bombing that killed 60 people.
Efforts to release Kassasbeh and Goto gained urgency with the release late Tuesday of a purported online ultimatum claiming ISIL would kill both hostages within 24 hours if Rishawi was not freed.
On Wednesday, Jordanian government spokesman Mohammad al-Momani said Jordan was willing to hand over Rishawi in exchange for the release of Kassasbeh. But Momani made no mention of Goto.
Momani said Jordan's priority was to secure the release of the pilot, who hails from an important Jordanian tribe, which forms the backbone of support for the Hashemite monarchy.
Japan is working closely with Jordan, Foreign Minister Fumio Kishida said on Wednesday. Goto's mother appealed for his life on Wednesday, begging Abe to save her son's life during a news conference.
"Please save Kenji's life. I call on you to work with all your strength in negotiations with the Jordanian government," she said.
Abe called on Jordan to cooperate in working for Goto's quick release, but vowed Tokyo would not give in to terrorism.
Al Jazeera and wire services