The revelation came after the Cabinet approved also Tuesday the emperor's resumption of official duties after health checks showed that he is steadily recuperating after his heart bypass surgery in February.
The Imperial Household Agency is looking into the possibility of the emperor and empress traveling to Britain to attend a ceremony on May 18 in celebration of the 60th anniversary of Queen Elizabeth's accession to the throne, Fujimura told a news conference.
The emperor had delegated performance of his state duties to Crown Prince Naruhito on Feb. 17, the day before his surgery.
Since being discharged from hospital on March 4, the emperor has mostly spent time in rehabilitation. But he has attended a few activities including a memorial ceremony in Tokyo on March 11 to mark the first anniversary of the disaster in northeastern Japan.