The Islamic State (IS) militant group has posted a video that purportedly shows the execution of Japanese hostage Kenji Goto, despite days of negotiations to win his release.
The Japanese government said it was still working to verify the authenticity of the video that was posted on January 31, but officials indicated it was likely genuine.
Japanese Prime Minister Shinzo Abe said, "I feel strong indignation at this inhumane and contemptible act of terrorism."
Abe said Japan will work with the international community 'to bring those responsible to justice."
Chief Cabinet Secretary Yoshihide Suga condemned the IS for posting the video. "I cannot help feeling strong indignation that an inhuman and despicable act of terrorism like this has been committed again," he said.
Suga announced relevant members of Japanese cabinet would meet to discuss a response.
The video reportedly shows a hooded man speaking with a British accent, blaming Japan's government for its support of coalition forces attacking the IS.
The militant then kills Goto.
There were reports earlier of a possible deal to gain Goto's release in exchange for Jordan freeing Iraqi would-be suicide bomber Sajida al-Rishawi.
Jordanian authorities hoped the deal could include the release of Jordanian pilot Muath al-Kasasbeh, who the IS has been holding captive since his plane came down Syria in December.
The January 31 video did not mention the Jordanian pilot.
The IS killed another Japanese hostage, Haruna Yukawa, a week ago.
U.S. President Barack Obama condemned Goto's "heinous murder" at the hands of IS militants and vowed the United States would continue efforts to destroy the extremist group.
British Prime Minister called the killing "appalling" and "despicable" and said "it is a further reminder that [IS] is the embodiment of evil, with no regard for human life."
French President Francois Hollande "resolutely condemned the brutal murder" and added, "France stands in solidarity with Japan."
Goto was a freelance journalist who covered wars in Africa, Afghanistan, and the Middle East.
He was captured by IS militants last October after he had gone to Syria to try to help secure the release of Yukawa.
The IS released a video on January 20 threatening to kill Yukawa and Goto unless the Japanese government paid a $200 million ransom within 72 hours.
After killing Yukawa, the IS changed its demand and reportedly offered to trade Goto for Rishawi.
Rishawi is on death row in Jordan for her role in a 2005 suicide bomb attack that killed 60 people in the capital, Amman.