Emir of Kuwait, Nawaf Al-Ahmad Al-Jaber Al-Sabah, passed away at the age of 86.
Kuwaiti state television interrupted regular programming with Koranic verses before announcing the Emir's death.
The cause of the Emir's death has not been disclosed to the public.
Sheikh Mohammed Abdullah Al Sabah, the minister of his emiri court, expressed sorrow and announced the Emir's passing on state television.
Emir Nawaf had been admitted to the hospital in late November due to a medical emergency, with the illness unspecified.
The tiny, oil-rich nation had been awaiting updates on the Emir's health since his hospitalization.
Emir Nawaf Al-Ahmad Al-Jaber Al-Sabah was born in 1937, the fifth son of Sheikh Ahmad al-Jaber Al-Sabah, who ruled Kuwait from 1921 to 1950.
He began his political career at 25 as the governor of Hawalli province and later served as the interior minister for a decade.
Crowned in 2006 by his half-brother Sheikh Sabah Al-Ahmad Al-Sabah, Nawaf became Emir in September 2020 following Sheikh Sabah's death.
The current crown prince, Sheikh Mishal al-Ahmad al-Sabah, is 83 years old and serves as Kuwait's deputy ruler, another half-brother of the late Emir.