Japan must do more to fight terrorism than continue to refuel ships in the Indian Ocean, Afghan Ambassador to Japan Haron Amin said Friday in Tokyo.

"No country can afford to choose isolation due to domestic politics" in the global effort to stabilize the region, Amin said.

However, the ambassador stopped short of detailing his demands to Tokyo, saying that Japan's role in Afghanistan is a "completely domestic issue" for discussion and debate.

Japan's cooperation in antiterrorism efforts in and around Afghanistan has reached a crucial juncture, with a special law that allows the Maritime Self-Defense Force to refuel multinational warships in the Indian Ocean due to expire in January.

The MSDF's operation was briefly halted last year after the opposition, led by the Democratic Party of Japan, voted against the dispatch.

The pullout "was only welcomed by militants and al-Qaida," Amin said in his speech, requesting that operations not be suspended a second time.

Prime Minister Taro Aso has said he would pursue extending the bill but the outlook remains unclear.

Meanwhile, Amin revealed to reporters that the investigation into the killing of aid worker Kazuya Ito in August is still ongoing, saying that Afghan authorities have so far determined that one of the four kidnappers was a paid Pakistani who was specifically ordered by an institution in Pakistan to kill a Japanese national.