TOKYO >> Japan’s crown prince believes efforts should be made to reduce the burden on his ailing father, Emperor Akihito, as the 78-year-old monarch recovers from heart bypass surgery.

Crown Prince Naruhito said that as Akihito gets older it is increasingly important to ensure that his official duties are not too heavy. Naruhito, the heir to the throne, made the comment in a news conference to mark his 52nd birthday on Thursday.

Akihito underwent the surgery on Saturday and remains in the hospital but is reportedly in good spirits. Emperors in modern Japan reign until they die. Naruhito refrained from commenting on whether that should be changed.

Japan’s postwar emperors are restricted to largely ceremonial functions.