"I only have 24 hours left to live"

A new message posted Tuesday to websites used by the Islamic State of Iraq and Syria (ISIS) included an audio statement, seemingly read by Japanese captive Kenji Goto, in which he relays the latest purported demands to secure his release.

"I only have 24 hours left to live," says the voice on the recording, which was accompanied by a new photo showing a man appearing to be Goto, who is himself holding a photograph of a Jordanian pilot also held by the terror group.

ISIS said in an online video on Jan. 20 that it had Goto and another Japanese man, Haruna Yukawa, and would kill them within 72 hours unless it was paid a ransom of $200 million.

Over the weekend, a new, unverified video showed a photo of Goto holding a picture of what appeared to be Yukawa's beheaded body. That message also came with an audio clip, claiming to be Goto, saying his captors had changed their demand to a prisoner swap. According to that audio, ISIS was demanding the release of an al Qaeda suspect held in Jordan in exchange for the lives of Goto and a Jordanian military pilot also in ISIS captivity.

The message released Tuesday, which CBS News could not independently verify the authenticity of, but which appeared on official ISIS media channels, renewed the offer to free Goto and the Jordanian in exchange for Sajida Rishawi, an attempted suicide bomber who has been held for years in Jordan.

A Jordanian official told CBS News on condition of anonymity that "this is a clear attempt to destroy the Jordanian-Japanese relationship."

"The Japanese parliament will never approve foreign aid to Jordan," the official said.

According to the Washington Post, ISIS' interest in Rishawi likely stems from her links to the slain founder of al Qaeda in Iraq, the group which would eventually morph into ISIS.

In the audio clip released Tuesday, the message purportedly read by Goto says the terror group intends to execute the Jordanian pilot first, and then Goto, if the prisoner swap is not arranged.

"Any more delays by the Jordanian government will mean they are responsible for the death of their pilot, which will then be followed by mine. I only have 24 hours left to live, and the pilot has even less," says the man in the recording, which concludes by suggesting "the ball is now in the Jordanians' court."

Jordanian Prime Minister Abdullah Ensour declined to comment, saying it would be "unproductive" to do so.

Meanwhile, another government source told a Jordanian news website that the "government studied the ISIS video carefully and found that that ISIS did not say that they will free the pilot if Jordan releases Rishawi."

Japanese officials have spent several days in Amman discussing the situation, but they have not made any public statements on what is being considered in the efforts to secure the hostages freedom.