AMMAN, Jordan — A spokesman says Jordan’s government has demanded proof of life of a Jordanian pilot held by Islamic State militants before moving ahead with any possible swap to bring about his release.

The militants have purportedly threatened to kill the pilot, Lt. Muath al-Kaseasbeh, by sunset unless Jordan frees an Iraqi woman from death row and delivers her to the Turkish border.

The woman, Sajida al-Rishawi, was involved in deadly Amman hotel bombings a decade ago.

Jordanian government spokesman Mohammed al-Momani said Thursday afternoon that al-Rishawi is still in Jordan, raising doubts that the sunset deadline, which will pass in less than an hour, can be met.

He says “we want to see a proof of life of the Jordanian pilot and then we can talk about the exchange.”