Crown Prince Naruhitio defers to Emperor Akihito

Japan's Crown Prince Naruhitio will only perform more official duties if his 77-year-old father Emperor Akihito asks him to.

The prince has revealed he is happy to take on more responsibility to lighten the load of official duties on his father but has no plans to step in and take control unless the emperor - who was diagnosed with arteriosclerosis (hardening of the arteries) earlier this month - requests it.

He said it is important to consider "not placing excessive burdens" on his father but reducing the workload "should proceed in line with the thoughts of his majesty, who is truly thinking a great deal about what he should do as Emperor".

The prince also revealed he and his wife Crown Princess Masako are doing everything they can to "create an environment" where their nine-year-old daughter feels safe at school after her "trying experience" last year when she was the victim of bullying.

Referring to his wife - who is being treated for a stress-related illness - Prince Naruhitio said she "is making as much effort as possible as a mother to let Aiko go to school the way she did before".