Japanese Prime Minister Shinzo Abe has called the apparent beheading of a Japanese captive by the Islamic State group "outrageous and impermissible."
The Japanese leader told public broadcaster NHK on Sunday that Japan will not give in to terrorism, and called for the immediate release of the remaining Japanese captive, free-lance journalist Kenji Goto.
The statements came a day after the IS group posted a video online that showed Goto holding up photos appearing to show beheaded co-captive, self-employed security contractor Haruna Yukawa.
In the video, a man's voice purporting to be Goto is heard in English with Arabic subtitles. The man directly addresses Abe, accusing him of responsibility for Yukawa's death. Goto said he would be freed in exchange for the release of Sajida al-Rishawi, a woman accused of attempting to become a suicide bomber, now imprisoned in Jordan.
U.S. President Barack Obama telephoned Abe Sunday from New Delhi to offer his condolences. He also thanked Abe for the humanitarian aid that Japan has provided to the Middle East region.
On Saturday, Obama strongly condemned "the brutal murder" of Yukawa, and vowed Washington and it allies would "bring the perpetrators...to justice."
U.S. Secretary of Defense Chuck Hagel released a statement Saturday saying Islamic State's "inhumanity stands in sharp contrast to the generous humanitarian aid Japan has provided to the Iraqi and Syrian people in recent months."
The Islamic State group, which now controls a third of both Syria and Iraq, had threatened Tuesday to behead the hostages within 72 hours unless it received a $200 million ransom.