Safi Yousef (2nd R), father of Islamic State captive Jordanian pilot Muath al-Kasaesbeh, reads a statement released by Islamic State during a demonstration to demand the Jordanian government negotiate with Islamic State for the release of Kasaesbah, in front of the Royal Palace in Amman January 28, 2015. [Photo/Agencies]

AMMAN - Jordan said on Wednesday it had received no assurance that one of its pilots captured by Islamic State insurgents was safe and that it would go ahead with a proposed prisoner swap only if he was freed.

The fate of air force pilot Muath al-Kasaesbeh was thought to be tied to that of Japanese hostage Kenji Goto, a veteran war reporter who is also being held by the insurgent group.

A video was released on Tuesday purporting to show the Japanese national saying he had 24 hours to live unless Jordan released Sajida al-Rishawi, an Iraqi woman on death row for her role in a 2005 suicide bomb attack.

Government spokesman Mohammad al-Momani said Jordan was ready to release al-Rishawi if Kasaesbeh was spared, but made clear that she was still being held until the pilot was freed.

"It's not true she has been released. Her release is tied to freeing our pilot," Momani told Reuters. He made no mention of Goto.

Foreign Minister Nasser Judeh said on his official Twitter account that a Jordanian request for proof that Kasaesbeh was safe and well had gone unanswered.

The Jordanian comments have raised concerns in Japan that Goto might no longer be part of any deal between Amman and Islamic State. But CNN quoted Judeh as saying that "of course" the Japanese hostage's release would be part of any exchange.