Japanese Emperor Akihito, who has been in a hospital with a bronchial infection, has a high fever and will likely put off all official duties for the rest of the month, Kyodo news agency reported on Tuesday, quoting the Imperial Household Agency.
Akihito, who will turn 78 in December, entered hospital earlier this month. Kyodo reported on Tuesday he has a fever of almost 39 degrees Celsius (102.2 Fahrenheit).
The agency said Akihito would likely not resume duties this month even if he left hospital.
Akihito was hospitalised on November 6 with a cold, fever and a bronchial infection.
He had initially been cleared to return to his palace and was due to be discharged last Friday, but stayed at the University of Tokyo hospital after his cough worsened and his fever went up.
Akihito, who ascended to the throne after the death of his father Hirohito in 1989, has spent much of the past two decades working to close the gap between the imperial family and the Japanese people.
Akihito made an unprecedented television address in March, five days after an earthquake and tsunami devastated Japan's northeast. He travelled to the disaster zone in April with Empress Michiko, 77.
Akihito had surgery for prostate cancer in 2003 and suffered stress-related health issues in late 2008, including irregular pulse and stomach bleeding.
The following year, the royal agency said he would cut back on official duties such as speeches and meeting foreign dignitaries.
(Reporting by Kaori Kaneko; Editing by Paul Tait)