Tokyo, Jan 22 (IANS): The Japanese government Thursday said it was considering all possible ways to ensure safe release of its two nationals held hostage by Islamic State(IS) militants.

IS, in a video, sought a ransom of $200 million for the release of two Japanese nationals who were taken hostage Tuesday, Kyodo News reported.

The Japanese government was trying Thursday to open negotiation channels to urge IS militants to release the two Japanese without harming them, as a 72-hour deadline for paying a ransom approaches without notable contact with the hostage-takers.

"We haven't been able to confirm the safety of hostages," Chief Cabinet Secretary Yoshihide Suga said in a press conference here. "Government is yet to hear directly from the group."

"We are exploring every possibility to save their lives," Suga added.

Japanese Foreign Minister Fumio Kishida Tuesday called on his US and French counterparts over the hostage crisis.