Tokyo, Jan 28 (IANS/EFE): Japanese Prime Minister Shinzo Abe said Wednesday that the situation of the Japanese journalist kidnapped by the Islamic State (IS) is "very difficult", after the radical group issued an ultimatum of 24 hours for the authorities to meet their demands failing which the journalist and a Jordanian pilot would be executed.

"Although the situation is very difficult, I have urged again the entire government to make every effort to secure the release of Kenji Goto as soon as possible," Abe was quoted as saying by public broadcaster NHK.

The prime minister said that Tokyo was working closely with the Jordanian government to achieve Goto's freedom.

The IS distributed a new audio message in which it gave an ultimatum of 24 hours to meet its demand of releasing Sayida Al Rishawi, an Iraqi woman who was arrested and sentenced to death in Jordan for a failed 2005 bombing.

If its demands are not complied with, the IS threatened to kill Goto, who has been held hostage since October, and also the Jordanian air force pilot Muaz Kasasbeh held since December.

In the audio message, Goto, 47, urged in English that Tokyo put pressure on the Jordanian authorities to release Al Rishawi or the jihadis will kill him and the pilot within 24 hours.

Abe said that the probability of the authenticity of the recording is very high, according to official sources quoted by NHK.

Although the idea of swapping hostages has been doing the rounds for a few days, neither Tokyo nor Amman have spoken clearly on the matter.

The newspaper Jordan Times said that even the US would have proposed a "2 2" exchange which would be to free the pilot and journalist in exchange for Al Rishawi and another jihadi sentenced to prison in 2008 by the Jordanian authorities.

Goto is one of the two Japanese hostages abducted by the IS, which Saturday announced the execution of the other captive, Haruna Yukawa.

It did so through a recording accompanied by an image of Goto holding a snapshot of Yukawa.