The IS has claimed they killed their Japanese captive Kenji Goto, 47, seven days after they beheaded his fellow captive Haruna Yukawa, 42.
"We are deeply saddened by this despicable and horrendous act of terrorism, and we denounce it in the strongest terms. To the terrorists, we will never, never forgive them for this act," Japanese Prime Minister Shinzo Abe said, according to broadcaster NHK, as cited by CNN. "
On Jan. 31, the ISIS released a video that seems to show the execution of Goto, two days after the new deadline set by the group for the release of possible suicide bomber imprisoned in Jordan.
Efforts are still on-going to authenticate the video but Japan's government spokesman Yoshihide Suga said Tokyo believes that the authenticity of the footage is highly probable, NBC News reported.
Covering child education, refugees, poverty, AIDS, wars and conflicts around the world, Goto was a Japanese freelance video journalist who went to Syria to help his friend Yukawa but was captured ad held hostage there by the IS in October 2014.
When Yukawa when to Syria, he described himself as a security consultant who would help expatriate Japanese companies in early 2013, when Islamist militants killed 10 Japanese energy workers in Algeria.
It must be noted that Japan is not involved in the military campaign against IS unlike the United States, Britain and other allies.
In a statement, U.S. President Barack Obama said Japan deserves praise for its "steadfast commitment to advancing peace and prosperity in the Middle East and globally."