Tokyo: Japan's deputy foreign minister has said negotiations with the Islamic State group (IS) threatening to execute Jordanian pilot Maaz al-Kassasbeh and Japanese journalist Kenji Goto have become ‘deadlocked’, local media reported Saturday.

"Staying vigilant, we will continue analysing and examining information as the government is making concerted efforts together” said Yasuhide Nakayama, who is leading Tokyo's emergency response team in Amman, reports Japan's public broadcaster NHK.

In Tokyo, deputy chief cabinet secretary Hiroshige Seko, said Saturday morning that the government was still waiting for new information on the hostage crisis.

IS had vowed to kill Kassasbeh by sunset on Thursday unless Amman hands over an Iraqi female jihadist in return for Goto.

Jordan has demanded evidence that the pilot, who crashed in Syria on 24 December, is still alive before freeing would-be suicide bomber Sajida al-Rishawi, who is on death row.

Jordan has offered to free Rishawi, who was convicted for her part in triple-hotel bombings in Amman in 2005 that killed 60 people, if IS releases the pilot.

The Jordanian government has been under heavy pressure at home and from Japan -- a major aid donor -- to save Kassasbeh as well as Goto.

While IS threatened Kassasbeh's life, it was not clear from its latest message if the jihadist group was ready to free him as part of an exchange.

IS had set the Thursday sunset deadline for Rishawi to be released at the Turkish border in return for Goto but there was no news of a swap.