Japan's Prime Minister vowed Tuesday to save the lives of two Japanese hostages, one a freelance journalist and the other a soldier for hire, threatened with beheading in an online video purportedly released by the Islamic State terror group.

In the video, identified as being made by the Islamic State group's al-Furqan media arm and posted on militant websites associated with the extremist group, a militant threatened to kill the men unless a $200 million ransom was paid within 72 hours. If confirmed to be from Islamic State, better known as ISIS, the video would mark the first public demand for ransom from the group in exchange for the release of captives.

Speaking in Jerusalem, Japanese Prime Minister Shinzo Abe called on ISIS to immediately release the hostages, saying that "their lives are the top priority." Abe is in the midst of a six-day visit to the Middle East, accompanied by more than 100 government officials and presidents of Japanese companies.

"It is unforgivable," he said. "Extremism and Islam are completely different things."

Abe said he would send Yasuhide Nakayama, a deputy foreign minister, to Jordan to seek the country's support and to resolve the hostage crisis. The premier also said the Israeli government, which Japan promised Sunday to cooperate with on counterterrorism, are sharing information to aid in the hostage crisis. The Israeli prime minister's office declined to comment.

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In the video, the two men, identified by ISIS as Kenji Goto Jogo and Haruna Yukawa, appear in orange jumpsuits like other hostages previously killed by ISIS, which controls a third of Iraq and Syria. The militant who threatens them speaks in a British accent and resembles a militant involved in other filmed beheadings.

"To the prime minister of Japan: Although you are more than 8,500 kilometers (5,280 miles) from the Islamic State, you willingly have volunteered to take part in this crusade," the knife-brandishing terrorist says. "You have proudly donated $100 million to kill our women and children, to destroy the homes of the Muslims."

Japan's Foreign Ministry's anti-terrorism section has seen the video and analysts are assessing it, a ministry official said. The official spoke on condition of anonymity because of department rules.

Speaking in Tokyo, Chief Cabinet Secretary Yoshihide Suga declined to say whether Japan would pay the ransom.

"If true, the act of threat in exchange of people's lives is unforgivable and we feel strong indignation," Suga told journalists. "We will make our utmost effort to win their release as soon as possible."

Yukawa, a 42-year-old private military company operator, was kidnapped in Syria in August after going there to train with militants, according to a post on a blog he kept. Pictures on his Facebook page show him in Iraq and Syria in July. One video on his page showed him holding a Kalashnikov assault rifle with the caption: "Syria war in Aleppo 2014."

"I cannot identify the destination," Yukawa wrote in his last blog post. "But the next one could be the most dangerous." He added: "I hope to film my fighting scenes during an upcoming visit."

Yukawa's father, Shoichi, who lives in Chiba, just outside Tokyo, expressed shock over the news in an interview with Japanese public television station NHK.

"I don't understand this," he said. "I'm quite confused."

Nobuo Kimoto, an adviser to Yukawa's company, told NHK that he had worried "something like this could happen sooner or later."

"I was afraid that they could use Yukawa as a card," Kimoto said.

Goto, 47, is a respected Japanese freelance journalist who went to report on Syria's civil war last year.

"I'm in Syria for reporting," Goto wrote in an email to an Associated Press journalist in October. "I hope I can convey the atmosphere from where I am and share it."

ISIS has beheaded and shot dead hundreds of captives -- mainly Syrian and Iraqi soldiers -- during its sweep across the two countries, and has celebrated its mass killings in extremely graphic videos. A British-accented jihadi also has appeared in the beheading videos of slain American hostages James Foley and Steven Sotloff, and with British hostages David Haines and Alan Henning.

The group also holds British photojournalist John Cantlie, who has appeared in other extremist propaganda videos, and a 26-year-old American woman captured last year in Syria while working for aid groups. U.S. officials have asked that the woman not be identified out of fears for her safety.

Tuesday's video marks the first time an Islamic State message publicly has demanded cash. The extremists requested $132.5 million from Foley's parents and political concessions from Washington, though neither granted them during months of negotiations before his killing, U.S. authorities say.

The Islamic State group has suffered recent losses in airstrikes by a U.S.-led coalition, and with global oil prices being down, their revenue from selling stolen oil likely has dropped as well. The extremists also have made money from extortion, illicit businesses and other gangland-style criminal activity.

Its militants also recently released some 200 mostly elderly Yazidi hostages in Iraq, fueling speculation by Iraqi officials that the group didn't have the money to care for them.

Japan relies on the Middle East for most of the crude oil it needs to run the world's third-largest economy. It also has been working to build wider economic ties in the region, like with Abe's current Mideast tour.

This is Abe's second Mideast hostage crisis since becoming prime minister. Two years ago, Al Qaeda-affiliated militants attacked an Algerian natural gas plant and the ensuing four-day hostage crisis killed 29 insurgents and 37 foreigners, including 10 Japanese who were working for a Yokohama-based engineering company, JCG Corp. Seven Japanese survived.

In 2004, followers of Jordanian militant Abu Musab al-Zarqawi in Iraq beheaded Japanese backpacker Shosei Koda and wrapped his body in an American flag over Japan having troops in Iraq doing humanitarian work. A video by al-Zarqawi's group, which later became the Islamic State group, showed Koda begging Japan's then-prime minister to save him.

The Associated Press contributed to this report.