Tokyo - Amman - Japan and Jordan were working closely on Friday to find out what had happened to two of their nationals being held by ISIS after a deadline passed for the release of a would-be suicide bomber being held on death row in Amman.
Japanese Prime Minister Shinzo Abe said every effort was being made to secure the release of journalist Kenji Goto.
Deadline passed
"We're gathering and analysing information while asking for co-operation from Jordan and other countries, making every effort to free Kenji Goto," he told a parliamentary panel.
Jordan said on Thursday it was still holding the Iraqi woman prisoner as a deadline passed for her release set by Islamic State militants, who threatened to kill a Jordanian pilot unless she was handed over by sunset.
An audio message purportedly from Goto said the pilot would be killed if Jordan did not free Sajida al-Rishawi, in jail for her role in a 2005 suicide bomb attack that killed 60 people in the Jordanian capital.
The message extended a previous deadline set on Tuesday in which Goto said he would be killed within 24 hours if al-Rishawi was not freed.
Released videos
Japanese chief cabinet secretary Yoshihide Suga said late on Friday that Tokyo was doing everything it could, but declined to answer whether negotiations had stalled and if there was any progress.
The hostage crisis comes as ISIS, which has already released videos showing the beheadings of five Western hostages, is coming under increased military pressure from US-led air strikes and by Kurdish and Iraqi troops pushing to reverse the Islamist group's territorial gains in Iraq and Syria.