Japan and the United States have condemned Islamic State extremists for the apparent beheading of a Japanese journalist, hours after a grisly Internet video showed the execution.
Japanese Prime Minister Shinzo Abe called the killing an "inhumane and contemptible act of terrorism" and vowed he would never forgive the killers. In Washington, President Barack Obama described the killing as "heinous murder."
The statements came hours after a video purported to show Japanese journalist Kenji Goto kneeling next to a hooded man who was holding a knife to the journalist's throat. The footage, which conforms to other beheading videos posted by the extremists, ends with a picture of a decapitated body.
Analysts said they thought the executioner had the same British accent as the killer featured in earlier IS execution videos.
The new video appeared two days after the latest deadline set by Islamic State militants demanding the release of an Iraqi prisoner.
On Friday, Japanese Foreign Minister Yasuhide Nakayama said in Amman, Jordan, that progress to secure the release of Jordanian pilot Mu'ath al-Kasaesbeh and journalist Goto had "become deadlocked."
Kasaesbeh was captured in December after his fighter plane was downed over an IS-controlled area of Syria. Saturday's video made no mention of the pilot.
Islamic State militants had threatened to kill Kasaesbeh if Jordan did not release Iraqi prisoner Sajida al-Rishawi by sunset Thursday. Rishawi is on death row in Jordan for her role in a deadly 2005 bombing in Amman.
Jordan said it would release Rishawi only with proof that its pilot was alive, and that no such evidence had been received.
Goto's wife, Rinko, issued an emotional appeal late Thursday to both Tokyo and Amman to save her husband's life. But the audio recording, apparently released by the Islamic State, did not promise that either of the hostages would be released in exchange for Rishawi.
Days ahead of Saturday's video, Islamic State released footage showing Goto holding pictures of another Japanese hostage, Haruna Yukawa, who had apparently been beheaded. In that video, a man's voice, identifying himself as Goto, directly addresses Japan's Abe, accusing him of responsibility for Yukawa's death.
Goto is believed to have been captured by Islamic State last year while trying to rescue Yukawa.
The hostage crisis comes as Islamic State militants have captured large areas of Iraq and Syria, declaring the region a caliphate that all other Muslims should follow.