TOKYO — The fates of a Japanese journalist and Jordanian military pilot were unknown today, a day after the latest purported deadline for a possible prisoner swap passed with no further word from the Islamic State group holding them captive.

“Government institutions are working around the clock on the case of pilot Muath al-Kaseasbeh,” Jordanian military spokesman Mamdouh al-Ameri said in a statement. “We will inform you of any developments in due time.”

He urged Jordanians not to listen to rumors.

Jordan has said it will only release an al-Qaida prisoner from death row if it gets proof the pilot is alive and so far has received no such evidence from the hostage-takers.

Officials in Tokyo also said they had no progress to report.

“There is nothing I can tell you,” said government spokesman Yoshihide Suga, reiterating Japan’s “strong trust” in the Jordanians to help save the Japanese hostage, freelance journalist Kenji Goto.

Suga said the government was in close contact with Goto’s wife, Rinko Jogo, who released a statement late Thursday pleading for her husband’s life.

An audio message purportedly posted online by jihadis said the pilot, Lt. Muath al-Kaseasbeh, would be killed if Sajida al-Rishawi, the al-Qaida prisoner, was not delivered to the Turkish border by sunset on Thursday, Iraq time. It was not clear from the recording what would happen to Goto if the Iraqi woman was not turned over by the deadline.

The authenticity of the recording could not be verified independently by the AP.