TOKYO β€” Japan's 84-year-old Emperor Akihito was advised to rest after feeling nauseous and dizzy early Monday and canceled or postponed his duties.

The Imperial Household Agency said Akihito's wife Empress Michiko called the palace doctor early in the morning after finding the emperor sweating profusely. It said his symptoms were caused by insufficient blood flow to the brain and the doctor was continuing to monitor his situation.

Akihito announced in December he would abdicate the Chrysanthemum Throne at the end of April 2019, citing health concerns, to be succeeded by his eldest son, Crown Prince Naruhito.

Michiko will go by herself to some of the meetings scheduled for Monday, the agency said, including a meeting with Princess Ayako, a daughter of Akihito's cousin.

Ayako recently announced she will marry a commoner, and Michiko will relay the emperor's congratulatory wishes, the agency said.

During the final months of his reign, Akihito and Michiko plan to revisit places key to Japan's and their own personal history.

They visited Okinawa this year and offered prayers for people who died there during World War II. And they returned to Fukushima, meeting with people forced out of their homes because of radiation leaking from the nuclear plant damaged in the March, 11, 2011, earthquake and tsunami.

While Japanese emperors are no longer viewed as divine, the elder royals are beloved and welcomed by well-wishers almost anywhere they go.