"The cabinet has decided to postpone the celebrations of the proclamation of the Crown Prince," Suga told a briefing.
The official added that the cabinet would set a new date later as the situation in the country goes back to normal, but noted that the event would likely take place within a year.
The ceremony was initially scheduled for April 19.
To date, the number of people confirmed to be infected with the novel coronavirus in Japan has surpassed 7,740, according to the NHK broadcaster’s data. Tokyo accounts for the biggest number of cases in the country, 2158.