Japanese prime minister Shinzo Abe has told French president Emmanuel Macron the future of the Renault-Nissan alliance was up to private shareholders.

"Prime Minister Abe said regarding the alliance, which is a symbol of Japanese-French industrial cooperation, it is important to maintain a stable relationship," a spokesman told Reuters in Buenos Aires where Abe and Macron met on the sidelines of the G20 summit.

"However, he said the future of the alliance is up to the private-sector shareholders. The government of Japan does not prejudge the future of the alliance."