Japan has officially announced $15.5m to fight "terrorism" in the Middle East and Africa, as Tokyo tries to demonstrate its resolve despite the murder of two citizens by the Islamic State of Iraq and the Levant (ISIL) group.

The amount, which was first reported in Japanese newspapers on Sunday, doubles the $7.5m in assistance that Foreign Minister Fumio Kishida pledged during a visit to Brussels in January.

Kishida said in a statement on Tuesday that the aid was part of Japan's effort to support "counterterrorism capacity building assistance in the Middle East/Africa", including border control, investigation and development of legal systems.

Vice Foreign Minister Yasuhide Nakayama will give details on the aid when he attends a global conference later this week in Washington, ministry officials said.

The announcement comes weeks after a Japanese journalist and his adventurer friend were murdered by members of ISIL, a group whose fighters control tracts of Syria and Iraq.

Prime Minister Shinzo Abe has come in for criticism over the timing of an earlier $200m Japanese pledge to help refugees fleeing ISIL-controlled areas.

Abe announced the cash in Egypt on January 17, saying Japan would "help curb the threat" of ISIL and give the money "for those countries contending with" the fighters.

Days later a video emerged in which a masked man demanded the same sum as a ransom for the life of the two Japanese hostages.

Over the following tense weeks, Abe repeatedly said Japan would not "give in to terrorism".

ISIL fighters later changed their demand to the release of a death row inmate from a Jordanian prison.

Tokyo pressed Jordan for its help, but ISIL eventually announced the killing of the pair as well as a Jordanian airman.

Source: AFP