ISIS hostage Kenji Goto
ISIS hostage Kenji GotoScreenshot

Japan's deputy foreign minister has said negotiations with the Islamic State (ISIS) terror group threatening to execute a Jordanian pilot and a Japanese journalist have become "deadlocked", local media reported Saturday.

Yasuhide Nakayama, who is leading Tokyo's emergency response team in Amman, told reporters in the Jordanian capital late Friday that there had been no progress in trying to secure the release of Japanese journalist Kenji Goto and airman Maaz al-Kassasbeh.

"It has become deadlocked," he said, according to Japan's public broadcaster NHK. "Staying vigilant, we will continue analyzing and examining information as the government is making concerted efforts together."

In Tokyo, deputy Chief Cabinet Secretary Hiroshige Seko, a key aide to Prime Minister Shinzo Abe, said Saturday morning that the government was still waiting for new information on the hostage crisis.

Later in the day, Abe met with Foreign Minister Fumio Kishida and Chief Cabinet Secretary Yoshihide Suga at the prime minister's residence.

He renewed orders for officials to maintain close cooperation with Jordan in a bid to secure the immediate release of the Japanese national.

Our prime minister told us to handle it with a sense of tension by closely coordinating with Jordan and other countries concerned, as the situation remains extremely severe," Suga told reporters after the meeting.

ISIS 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 December 24, 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 ISIS releases the pilot.

Amman has been under heavy pressure from Tokyo - a major aid donor - to save Goto, as well as calls from Jordanians to bring Kassasbeh home.  

While ISIS 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.

ISIS 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.

Japan, which plays no military part in the fight against ISIS, was thrust onto the front line last week when a video appeared in which Goto and Haruna Yukawa, a self-described contractor, were seen kneeling in the desert.

A masked, knife-wielding terrorist said Tokyo had 72 hours to pay a $200 million (175 million-euro) ransom if it wanted to spare their lives.

When that deadline expired, new pictures appeared to show Yukawa had been beheaded, and a voice identifying itself as Goto demanded the release of Rishawi.

AFP contributed to this report.