The deadline to pay a ransom for two Japanese hostages of the Islamic State group or risk their execution loomed Friday, without any signs of progress on securing their release.

Prime Minister Shinzo Abe convened his National Security Council to discuss how to handle the expected deadline, as the mother of one of the captives appealed for her son's rescue.

The status of efforts to free the two men was unclear, with hours to go before the 72-hour deadline mentioned in a ransom video received by the Japanese government on Tuesday.

With time running short, Junko Ishido, the mother of 47-year-old journalist Kenji Goto, made a tearful appeal on his behalf.

"Time is running out. Please, Japanese government, save my son's life," said Junko Ishido, who described herself as an educator.

"My son is not an enemy of the Islamic State," she said in a tearful appearance in Tokyo.

Ishido said she was astonished and angered to learn from her daughter-in-law that Goto had left less than two weeks after his child was born, in October, to go to Syria to try to rescue the other hostage, 42-year-old Haruna Yukawa.

"My son felt he had to do everything in his power to try to rescue a friend and acquaintance," she said.

In very Japanese fashion, Ishido apologized repeatedly for "all the trouble my son has caused."

The national broadcaster NHK reported early Friday that it had received a message from Islamic State "public relations" saying that a statement would be released soon.

Lacking clout and diplomatic reach in the Middle East, Japan has scrambled for a way to secure the release of the two men, one a journalist, the other an adventurer fascinated by war. Two Japanese who said they have contacts with a leader in the Islamic State group offered Thursday to try to negotiate, but it was unclear if the Japanese government was receptive to the idea.

Ishido said she had not had any contact with the government.

The militants threatened in their video message to kill the hostages unless they received $200 million within 72 hours.

Government spokesman Yoshihide Suga reiterated Friday that Japan was trying all possible channels to reach those holding the hostages, and that its policy of providing humanitarian aid for those displaced by conflict in the Middle East was unchanged.

"We are doing our very best to coordinate with related parties, including through tribal chiefs," Suga said.

Suga confirmed Thursday that the government had confirmed the identity of the two hostages, despite obvious discrepancies in shadows and other details in the ransom video that suggest it may have been altered.

Japanese officials have not directly said whether they are considering paying any ransom, but said their lives were the top priority.

Japan has joined other major industrial nations of the Group of Seven in opposing ransom payments. U.S. and British officials also said they advised against paying.

Tokyo lacks strong diplomatic connections in the Middle East, and Japanese diplomats left Syria as the civil war there escalated, adding to the difficulty of contacting the group holding the hostages.

There was no sign the government had taken action on an offer to try to negotiate with the Islamic State group by Ko Nakata, an expert on Islamic law and former professor at Kyoto's Doshisha University, along with freelance journalist Kousuke Tsuneoka.

Nakata and Tsuneoka, who both are converts to Islam, said Thursday that they have a contact in the Islamic State group and were prepared to go.

Nakata and Tsuneoka, who was released after being held hostage in Afghanistan in 2010, visited Syria in September in an unsuccessful attempt to gain Yukawa's release. Goto was seized sometime after late October when he entered the area.

Since Japan's military operates only in a self-defense capacity a home any rescue attempt would require help from an ally like the United States.