Japane's Prime Minister Shinzo Abe (3rd R) bows as he attends a ministerial meeting at the prime minister's official residence in Tokyo February 1, 2015. [Photo/Agencies]

 

"Kenji has died, and my heart is broken. Facing such a tragic death, I'm just speechless," Goto's mother Junko Ishido told reporters.

"I was hoping Kenji might be able to come home," said Goto's brother, Junichi Goto, in a separate interview. "I was hoping he would return and thank everyone for his rescue, but that's impossible, and I'm bitterly disappointed."

According to his friends and family, Goto traveled to Syria in late October to try to save Haruna Yukawa, 42, who was taken hostage in August and who was shown as purportedly killed in an earlier video.

"He was kind and he was brave," said Yukawa's father Shoichi. "He tried to save my son."

"It's utterly heartbreaking," he said, crying and shaking. "People killing other people _ it's so deplorable. How can this be happening?"

Abe vowed not to give in to terrorism and said Japan will continue to provide humanitarian aid to countries fighting the Islamic State extremists.

The White House released a statement in which President Barack Obama also condemned "the heinous murder" and praised Goto's reporting, saying he "courageously sought to convey the plight of the Syrian people to the outside world."

Japan's defense minister, Gen Nakatani, said the police agency deemed the video of Goto's killing "highly likely to be authentic."

Highlighted by militant sympathizers on social media sites, the video bore the symbol of the Islamic State group's al-Furqan media arm.

A few dozen people, bundled up against a biting wind, gathered in front of Abe's official residence in downtown Tokyo Sunday afternoon to show their sympathy for the hostages.

"I feel so sad and angry. Why didn't the government rescue Kenji?" said Mayuko Tamura, 31, a pediatrician who came with her husband and their 8-month-old baby.