International media reports say Japan's ageing Emperor Akihito will step down in April 2019.
Prime Minister Shinzo Abe announced the abdication date shortly after a government and royal panel met to discuss the timing, according to the BBC.
The 83-year-old emperor had reportedly said last year that his age and health would make it difficult to fulfill his duties.
The timing of his abdication, the first in more than two centuries, has been the subject of debate in Japan.
The Imperial Household Council, made up of Prime Minister Shinzo Abe, lawmakers, and members of Japan's royal family, convened on December 21 to set the date of the abdication.
Mr. Abe later met reporters briefly to announce that they had decided the emperor would step down on April 30, 2019.
The BBC says his abdication will mark the end of the Heisei era, and he would be immediately succeeded by his son Crown Prince Naruhito on May 1, which would start a new imperial era.
The emperor has no political powers but several official duties, such as greeting foreign dignitaries. Japan's monarchy is entwined in the Shinto religion and the emperor still performs religious ceremonies.
Most people reportedly support the emperor's desire to abdicate – a survey conducted by the Kyodo news agency after Akihito suggested he wanted to step down found more than 85% saying abdication should be legalized.
The emperor, who has had heart surgery and was treated for prostate cancer, has been on the throne in Japan since the death of his father, Hirohito, in 1989.
