Japanese Prime Minister Shinzo Abe said his country is in a "race against time" to free two hostages being held by the Islamic State group for a $200 million ransom.
Abe told reporters Wednesday in Tokyo that he has instructed officials to use every possible diplomatic channel to secure the release of Kenji Goto and Haruna Yukawa.
Islamic State militants released a video Tuesday saying they would kill the men unless Japan paid the money within 72 hours, linking the threat to what they said was Japan's support for efforts to fight the group.
The prime minister said Wednesday that Japan "will never give in to terrorism." He has pledged $200 million in non-military aid to those countries affected by the Sunni extremists.
Japan is not among the countries directly participating in the coalition battling insurgents in Syria and Iraq.
However, Japanese citizens have previously been killed by Islamic militants - the most notable attack was at an Algerian gas plant in 2013 where ten Japanese died.