Japan and Indonesia agreed Wednesday to develop infrastructure and promote the fishing industry on six outer islands, including Natuna on the southern edge of the South China Sea where foreign fishing vessels continue to operate illegally.

The agreement was reached in talks between Indonesian Maritime Affairs and Fisheries Minister Susi Pujiastuti and Hiroto Izumi, a special adviser to Prime Minister Shinzo Abe.

Japan will help Indonesia to build fishing ports and fish markets on Natuna, Sabang, Morotai, Saumlaki, Moa and Biak islands, according to a joint statement.

The waters around the six islands are seen as having good potential for harvesting tuna and other kinds of fish for export to Japan, which is the largest importer of Indonesian tuna.

Japan has also agreed to help Indonesia set up radar on Natuna and other outer islands to detect illegal fishing activity, Izumi said.

The statement says Indonesia and Japan "share common interest in maintaining and promoting free, open and stable seas for peace, stability and prosperity of the region."

It says cooperation to improve maritime infrastructure, maritime safety and maritime industries is an important way to enhance bilateral relations.

Last December, the two countries formally agreed to set up the Japan-Indonesia Maritime Forum to this end.