AKIPRESS.COM - The mother of a Japanese journalist held captive by Islamic State militants along with another Japanese citizen appealed for his safe release on Friday as a ransom deadline neared and the government acknowledged it was in an "extremely severe situation".

Prime Minister Shinzo Abe has said saving the men's lives is paramount but that Japan will not bow to terrorism, reports Reuters. 

In an online video released on Tuesday, a black-clad figure holding a knife stood between journalist Kenji Goto and troubled loner Haruna Yukawa, threatening to kill them if Tokyo did not pay Islamic State $200 million within 72 hours.

The Japanese government considers the deadline to be 2:50 p.m. local time (0550 GMT) on Friday.

"My son Kenji is not an enemy of the people of the Islamic faith. I can only pray as a mother for his release," Goto's mother, Junko Ishido, told a packed news conference, choking back tears. "If I could offer my life I would plead that my son be released, it would be a small sacrifice on my part.

"He only went to rescue his friend. He has always looked out for weaker people, he was always helping weaker children than him," she added.

Abe has ordered his government to make every effort to secure their safe release, setting off a flurry of activity among Japanese diplomats.The captor in the video, which resembles those showing previous Islamic State captives, says the ransom demand matches the $200 million in aid that Abe pledged to help countries fighting Islamist militants.

Abe made the pledge during a multi-nation visit to the Middle East earlier this week. Islamic State militants have seized large areas of Iraq and Syria, and beheaded several Western captives.

Japan has stressed that its donation is for humanitarian aid, such as helping refugees, and insisted that it will not bow to terrorist threats.