Japan vowed Saturday that it won't give up "until the very end" to secure the release of the two hostages held by the Islamic State group for a $200 million ransom. A deadline of 72 hours to pay the ransom passed on Friday with no word from ISIS on the fate of the two Japanese nationals -- Kenji Goto and Haruna Yukawa.

In a video, released Tuesday, ISIS threatened to behead the two hostages if the ransom was not paid. A message posted on a forum popular among ISIS militants and its sympathizers warned that the “countdown has begun” to kill the two hostages, reportedly believed to be held in Syria.

"We will not rule out any possibility, and we are verifying all information thoroughly," Deputy Foreign Minister Yasuhide Nakayama, who is heading the rescue efforts, said, according to The Associated Press. "We will not give up until the very end to rescue the two so we can go home together."

"It is a very difficult path to see their release, despite a variety of routes. We are focusing on scrutinizing information over again,” he reportedly said.

Foreign Minister Fumio Kishida said that there was "nothing new to report" about the two hostages held by the Sunni militant group, according to Channel News Asia. Kishida held a meeting of an emergency taskforce early on Saturday.

"The situation remains severe, but we are doing everything we can to win the release of the two Japanese hostages," Japanese Chief Cabinet Secretary Yoshihide Suga said Friday, adding that the country was trying all possible channels to contact ISIS.

Goto’s mother on Friday pleaded for the safe release of her son, saying that he “is not an enemy of the people of the Islamic faith.”