A new audio message purportedly from hostage Kenji Goto on Thursday morning declared that Jordan must present female prisoner Sajida al-Rishawi at the Turkish border by sunset on Thursday, or Jordanian air force pilot Mu’ath al-Kaseasbeh would be executed immediately.

Twitter accounts linked to the Islamic State group posted the recording, accompanied by Arabic subtitles, on Thursday morning.

“I’m Kenji Goto Jogo,” the speaker said in English. “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 time, the Jordanian pilot Mu’ath al-Kaseasbeh will be killed immediately.”

Chief Cabinet Secretary Yoshihide Suga on Thursday told a news conference in Tokyo the government believes the voice is probably that of the missing journalist.

The message effectively extended the 24-hour deadline the Islamic State group set a day earlier to kill both Goto and the pilot unless Amman releases al-Rishawi, the would-be suicide bomber whose explosives failed during coordinated attacks on upscale hotels in Amman in 2005. That deadline expired at around 11 p.m. Wednesday.

The new deadline was to fall at around 5:30 p.m. local time, which corresponds to 11:30 p.m. Thursday Japan time. The new message suggested the Islamic State group was trying to seal a prisoner swap with Jordan.

But asked about the message, a high-ranking Japanese official on Thursday morning warned that a satisfactory outcome should not be a foregone conclusion. The group is just “trying to draw world attention,” the official said. “The situation still remains very tough.”

Jordan said Wednesday it is ready to free al-Rishawi if the Islamic State group releases al-Kaseasbeh, an air force pilot whose jet crashed in Syria in December. Jordanian officials, however, did not mention Goto in their public statements, raising concerns in Japan that Goto may no longer be considered a part of the deal.

On Thursday night, NHK, quoting local media outlets in Jordan, reported that Jordanian Prime Minister Abdallah Ensour held a meeting with parliamentary leaders to discuss the hostage crisis and that a news conference would be held “in several hours.”

Jordanian Foreign Minister Nasser Judeh told CNN on Wednesday that Amman has not forgotten Goto, even though his government’s announcement stopped short of mentioning the journalist.

Goto’s release would “of course” be part of a prisoner exchange, Judeh told the TV network, but the priority for Jordan is al-Kaseasbeh’s freedom.

According to local news reports, the pilot’s father, Safi al-Kaseasbeh, met with King Abdullah at the royal palace in Amman late Wednesday and the king assured him that his son would be saved.

Asked about Jordan’s stance, the senior Japanese official said it is understandable that Jordan prioritizes the pilot over Goto in official comments.

“It’s a matter of course for Jordan,” said the official.

“Jordan has its own public opinion,” the official said.

The pilot is a member of a prominent Jordanian family and members of the public there have been quoted saying the government should prioritize the pilot over Goto in any swap.

Motohiro Ono, a noted Middle East expert and a Democratic Party of Japan lawmaker, said the worst-case scenario for Jordan is that Goto alone would be freed in exchange for al-Rishawi and the pilot would be killed. Amman is desperately trying to avoid this, Ono said.

Meanwhile, the new Internet message shows the extremists are trying to demonstrate that it is they, not Jordan, who now have the upper hand, Ono said.

In a Lower House Budget Committee meeting Thursday, Prime Minister Shinzo Abe confirmed that his administration is relying on Amman’s assistance in the matter. Japan is “asking for Jordan’s cooperation” to save Goto, he said.

“We are making utmost efforts so that Mr. Goto will be released quickly,” he said.

Goto’s family members have suffered from the rapid to and fro and his repeated brushes with execution.

Fellow hostage Haruna Yukawa was apparently beheaded last week.

Full coverage of the Islamic State hostage crisis