Relatives of Lt Moaz al-Kasasbeh say they want more information
Jordan has vowed to do all it can to secure the release of a pilot captured by Islamic State, after a video was released appearing to show the beheading of a Japanese hostage.
Jordan echoed Japan in strongly condemning the murder of Kenji Goto.
The pilot, Lt Moaz al-Kasasbeh, was captured when his plane came down in December on a mission to support the US-led, anti-IS military coalition.
Jordan says it is willing to exchange an Iraqi prisoner for his safe return.
Government spokesman Mohammed al-Momeni told the official Petra news agency the administration was doing "everything it can to save the life and secure the release of its pilot".
He said: "All state organisations have been mobilised to secure the proof of life that we require so that he can be freed and returned to his home."
Analysis: Kevin Connolly, BBC News, Amman, Jordan
Very little has been heard of Lt Kasasbeh since he fell into the hands of the militants - his family continue to hope and pray for his safety and want their government to do more and to share more of whatever information it may have with them.
They cling to the hope that the killing of Kenji Goto doesn't necessarily have direct immediate implications for the safety of the young pilot.
The danger for the Jordanian government is that Islamic State may see Lt Kasasbeh as a hostage of particularly high value because of his role in the air campaign and may demand a very high political price for his freedom - if they can prove that he is still alive.
Mr Momeni also said that Jordan had "spared no effort, in coordination with the Japanese government" to save the life of Mr Goto.
Relatives of Lt Kasasbeh urged the government to do more for him and provide more information.
Yassin Rawashda, an uncle of the pilot, said: "We want the government to tell us the truth."
The latest video made no mention of Lt Kasasbeh.
His father, Safi, told Associated Press: "This is my son. I'm always concerned about him and any development makes me more concerned."
Kenji Goto's friend Mark Tchelistcheff: "Our hearts are very heavy with this news"
Lt Kasasbeh's F-16 crashed in IS-held territory in Syria in December. The US-led coalition has been targeting IS with air strikes since September.
The first IS demand, last week, had been for $200m (£130m) in return for two Japanese hostages - Mr Goto and Haruna Yukawa.
After a 72-hour deadline passed, IS said it had beheaded Mr Yukawa.
IS then demanded the release of Sajida al-Rishawi, on death row in Jordan for her role in hotel bombings in Amman in 2005 that killed 60.
It gave a deadline of sunset on Thursday for a deal under which Mr Goto would be freed in return for Rishawi.
Shinzo Abe condemned the killing of Mr Goto, calling it a "heinous act"
The news left Mr Goto's mother Junko Ishido distraught
Support for Kenji Goto in Tokyo
However, Jordan demanded that Lt Kasasbeh also be released and called for proof he was still alive.
The video showing the apparent beheading of Mr Goto brought the renewed offer from Jordan on Sunday of an exchange for Rishawi.
Mr Goto, 47, a respected journalist known for his work covering the suffering of civilians in war zones, went to Syria in October, reportedly to try to secure Mr Yukawa's release.
Japanese Prime Minister Shinzo Abe said on Sunday he "would not give in to terrorism" and that he would expand his support to countries fighting IS.
Prime Minister Abe said Japan would work with the international community to bring those responsible for Mr Goto's apparent murder to justice
The latest video, which has all the hallmarks of previous IS propaganda videos, has not been authenticated, but Japanese officials believe it is genuine.
In the video, Mr Goto is seen kneeling in an orange jumpsuit.
A militant speaking with an English accent who is believed to have appeared in previous videos and is known as "Jihadi John", addresses Mr Abe, accusing him of a "reckless decision to take part in an unwinnable war".
Mr Abe called the killing a "heinous act", adding that Japan would work with the international community to bring those responsible for Mr Goto's apparent murder to justice.
Mr Goto's mother Junko Ishido said she was speechless at his death, saying he had gone to Syria out of "kindness and courage".
