Japan and Jordan were working closely on Friday to find out what had happened to two of their nationals being held by Islamic State, 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.
"We are gathering and analysing information while asking for cooperation 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 Amman.
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.
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.
"We are doing the things we have to, one after the other, steadily," he told a news conference.
The hostage crisis comes as Islamic State, 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.
JORDAN DEMANDS PROOF
About an hour before the new deadline was due to pass on Thursday, government spokesman Mohammad al-Momani said Jordan was still holding al-Rishawi.
"We want proof ... that the pilot is alive so that we can proceed with what we said yesterday; exchanging the prisoner with our pilot," Momani told Reuters.
The pilot, Muath al-Kasaesbeh, was captured after his jet crashed in northeastern Syria in December during a bombing mission against Islamic State.
Momani said separately that Jordan was coordinating with Japanese authorities in an effort to secure the release of Goto, a veteran war reporter.
Goto's wife urged both governments to work for her husband's release, saying she feared this was his last chance.
In the latest audio recording purportedly of Goto, he said that Kasaesbeh would be killed "immediately" if al-Rishawi was not at the Turkish border by sunset on Thursday, Iraq time, ready to be exchanged for the Japanese hostage.
That was some time around 1430 GMT on Thursday.