Tokyo defended its confiscation of a Japanese journalist's passport on Monday as the journalist, a photographer, prepared to travel to Syria to cover refugee camps.

Chief Cabinet Secretary Yoshihide Suga said the government took travel documents away from Yuichi Sugimoto, 58, for his own safety, after learning of his plan.

"Islamic State has expressed its resolve to continue killing Japanese," Suga said. If a Japanese national enters Syria, he said, "we have assessed that there is a high risk that the person would face immediate danger to his life, like being captured by Islamic State or other extremists".