Prime Minister Shinzo Abe instructed Cabinet members to step up efforts to ensure the safe return of Kenji Goto, a 47-year-old freelance journalist taken hostage by a group believed to be the Islamic State.
"I want you to make all-out efforts to rescue Goto as soon as possible," Abe told the ministers during an official meeting Monday morning.
The Islamic State is demanding the release of Sajida al-Rishawi, a would-be suicide bomber detained on death row in Jordan, in exchange for Goto's release.
Chief Cabinet Secretary Yoshihide Suga stressed that the government is doing everything it can to have Goto freed.
"In cooperation with relevant countries, religious organisations and tribal leaders, we are doing our utmost [to save Goto] by using all channels we have," Suga said at a press conference Monday morning.
The Foreign Ministry, meanwhile, held an emergency meeting on the day and confirmed that it will continue diplomatic efforts in cooperation with a task force set up in Amman.
Regarding the video showing a photo of what appears to be the body of Haruna Yukawa, which was posted on the Internet on Saturday night, Suga said that based on various information, the killing was committed by people related to the Islamic State.
Asked about whether the government considers a man's voice in the video to be Goto's, Suga said, "We cannot deny that it was his. It is highly likely [that it was his]."