Japan on Sunday said it was "outraged" after the Islamic State group released a video purportedly showing the beheading of Japanese hostage Kenji Goto.
"We can't help but feel extremely outraged at the repeat of another heinous and despicable terrorist act," government spokesman Yoshihide Suga told a press conference in Tokyo.
"Again, we strongly condemn it."
Suga did not comment on whether Tokyo thought the video was credible.
In it, Goto is seen kneeling, dressed in an orange outfit, as a masked man standing beside him with a knife blames the Japanese government for his "slaughter."
It ends with a still photo of the body with the head resting on the back.
Yasuhide Nakayama, Japan's deputy foreign minister, had said negotiations with the militant group were "deadlocked", local media reported on Saturday.
Last week, a video appeared in which Goto and Haruna Yukawa, a self-described contractor, were seen kneeling in the desert.
A masked, knife-wielding militant said Tokyo had 72 hours to pay a $200 million (175 million-euro) ransom if it wanted to spare their lives.
When that deadline expired, new pictures appeared to show Yukawa had been beheaded.