The United States on Tuesday demanded the “immediate release” of two Japanese hostages threatened with beheading by Islamic State (ISIS) terrorists.

“The United States strongly condemns ISIL’s threat to murder Japanese citizens,” State Department spokeswoman Jen Psaki said, referring to ISIS by an alternate acronym.

“We call for the immediate release of these civilians and all other hostages. The United States is fully supportive of Japan in this matter,” she said, adding that US Secretary of State John Kerry would speak later in the day with his Japanese counterpart.

The Islamic State terrorist organization is demanding a $200 million ransom for the return of the two Japanese hostages – freelance journalist Kenji Goto and businessman Haruna Yukawa. Tokyo has vowed not to give in to terrorism.

In footage posted on jihadist websites, a black-clad terrorist brandishing a knife addresses the camera in English, standing between the two hostages, who are wearing orange jumpsuits.

“You now have 72 hours to pressure your government into making a wise decision by paying the $200 million to save the lives of your citizens,” he says, addressing Japanese nationals.

The terrorist justifies the callous ransom demand as a response to non-military aid that Japanese Prime Minister Shinzo Abe pledged to support countries affected by ISIS violence at the start of his Middle East tour in Egypt on Saturday.

But Abe, before leaving Jerusalem, pledged to honor his promise of aid and not cave in to terrorism, vowing to make all efforts to rescue the two captives.

AFP contributed to this report.